In the most secret room in the most secret house in Britain, four people stood and stared at a little piece of paper. The words on it weren't all that important – a weather report in German, of all things. But what they represented? Oh, yes.

The code machine used by German High Command had been broken. And, for the first time, it hadn't been a parahuman that had done it.

"Well," said Sarah Livsey, whose job had just been taken by a machine. "That's a bloody relief."

The machine in question was called Colossus. Although it barely fit in the room, filling it with a mess of wires and valves and tape, that was only half of the meaning behind the name. It was an enormous idea, a massive undertaking that could change the course of the war – and much, much more besides.

Colossus had been designed to crack the most complex code the Germans had come up with in the War. This was saying something. Enigma had been bad enough, and the bombe machines could only still decode them thanks to a lot of caution and a lot of luck.

As it was, the Allies couldn't act on any information they'd received solely on the strength of Enigma decodes. There had to be another plausible explanation, like treachery or spying or Master-based subversion. You couldn't put a direct Enigma decode into any message you were sending, or even mention the fact that you'd decoded a message to begin with. If the Germans changed their protocols for using Enigma to make it more secure or, God forbid, found out that the Allies could crack it, well, the bombes simply wouldn't be able to keep up. And thousands of soldiers and sailors would die.

Even with this, though, Enigma was a piece of cake to deal with compared to what the German High Command were using. They called it the Lorenz SZ-40. British intelligence called it the Tunny. It was used for secret teleprinter communication between the German military leaders, and even Hitler himself. If Bletchley Park could intercept and decode it reliably, they would be able to see inside the mind of the German war machine at the highest level.

Unfortunately, they couldn't. The Tunny was far, far more complex than Enigma was, and guarded far more jealously. Bletchley Park had at least managed to recreate the thing based off what they could deduce about how it worked. John Tiltman had laid the groundwork. Bill Tutte had come up with a design, and had even predicted a vulnerability in the Tunny given certain settings – a non-random element that could, theoretically, be used to break the code. In practice, however, it would have meant working through thousands of calculations. Bletchley recruited from the best, reaching out to universities all across the country for their brightest stars, but no-one was that good.

Currently, in fact, there was only one person who'd ever managed to break the Tunny code – Sarah Livsey, who cheated by skipping past most of the brainwork with her power and spent most of the rest of her time lying down with an icepack on her head. She'd been invaluable when it came to intuiting the design of the Tunny, as well. It wasn't an exaggeration to say that the project would be months or years behind schedule without her help. She was possibly the most important sixteen-year-old in the country, although she acted a lot older.

"I'll be honest, I never thought I'd see the day," said Tommy Flowers, who'd designed and built the Colossus. When he was excited, like this, his East London accent shone through especially strongly He adjusted his glasses, and grinned. "But we really done it, ain't we?"

"It's possibly a little too early to celebrate just yet," said Alan Turing, who'd come up with the whole concept in the first place. "It's managed to decode one message, one time. I agree it's encouraging, but we'll need to see if it can reliably crack whatever we put through it."

Using electro-mechanical machines to work through calculations had been Alan's brainwave. The idea of the machines wasn't new – the bombes were counting engines, for instance. Given a stream of input data, they would use their algorithms, the instructions they'd been designed with, to process it and try new combinations. They clicked through possibilities faster than humanly possible, which was of course the point.

The bombes couldn't handle all the possibilities of Enigma by themselves. But, when you added in the human element to narrow things down – like expecting a time and date stamp at the head of every message, like expecting a standard signature at the bottom – they could work through the resulting pool, which was still large but not infeasible. The Tunny, though? That was beyond the bombes.

What was new about Colossus – what had never been done before – was having a machine where you could alter not just the data, but also the very instructions the machine was following. It was like redesigning an engine on the fly to make it better at running at whichever speed you happened to be using. Colossus managed this by having a series of wired inputs, like a telephone operator's switchboard.

That had been Alan Turing's big idea. He called it the 'Universal Engine', because it could theoretically be used to calculate… well, anything. Break down any number of statements into their simplest binary components – what made each part of it true and false – and feed them into the Universal Engine along with whatever you wanted to do with them, and it would be able to provide an output.

Something like that was potentially huge for the field of mathematics, so it was unfortunate that Colossus wasn't actually a Universal Engine. Even then, it might never have been a possibility at all if not for Tommy's engineering genius, Sarah's superhuman intuition, and most especially the fourth person in the room.

"Oh, don't be such a worrywart, Alan. This is a fantastic creation! Feel a little pride! You've done well – we've all done well." Andrew Richter could hardly keep the grin off his face.

Richter was the only non-Brit in the room, instead hailing from Deer Lake, Newfoundland and on-loan from Canadian Intelligence. He didn't quite have Alan's genius for mathematics, or Tommy's engineering savvy, or Sarah's powers, but somehow managed to combine all three. He'd taken to the Colossus project like a duck to water, with a passion and drive that was relentless and astonishing. His talent for working with Colossus, and machines like it, was equally amazing. Alan would have sworn that he'd worked on something like this before, if that hadn't been literally impossible. In everyday life, he was small and unassuming, almost introverted. But when he found something he was truly passionate about, he would work for hours on end in a mad frenzy. He reminded Alan of nothing so much as a Tinker, although Richter swore he was no good at building things.

"It's certainly something, I'll grant you," Alan said. "I'm excited to see where you take it next."

"You're not staying on the project?" Tommy asked.

"No," said Alan, a little wistfully. "No, I'm being put on speech encryption. If we can get that working, we can send secure messages by voice, rather than faffing around with telegrams and Morse code all the time. Make things easier on the chaps in the field, you know. In any case, now that Colossus has shown its worth as a proof-of-concept there's nothing more for me to do here. It's a shame we couldn't get the Universal Engine, but I'm truly thankful for what we do have."

"That won't do," said Richter, putting down his tea and frowning. "Where's your sense of ambition, man?"

"I'm sorry?"

"Look, the Colossus is a landmark achievement in both mathematics and telecommunications. But it could be so much more. Don't you want to realise your true vision?"

"Of course I do," Alan protested. "But the higher-ups would never go for it, you know that. They've got their code-breaker – no point wasting time on pie-in-the-sky fancies, that's what they'd say, not with a war on. Besides, I really do need to work on speech encryption. Like it or not, it really is more important right now."

"Well, I say it's a damn shame. Tommy, Miss Livsey, you want to push this thing as high as it can possibly go, right?"

Sarah yawned, and stretched. "Right now, I want to sleep for about a month in a cool dark room. I suspect some general or other is going to desperately need some insight into what Fritz is planning in Africa or somewhere, though, so I'd better turn in early and rest while I can." She looked at Richter speculatively. "Having said that, if you really have had a brainwave, then of course I'm in. This has been a welcome break from the usual."

Richter clapped his hands. "Good, good! And you, Tommy? Come on, I know you want a chance to show everyone what you can do."

Tommy shrugged. "Can't deny I'd like to finish the job, now you mention it. Go on then, what's your idea?"

"Look here," Richter said. He marched over to one of the secure cabinets, opened it, and withdrew the blueprints for Colossus with a flourish. They went down on a desk with a small slap. "For a start, we can save a lot of space by cutting out the vacuum tubes. Instead, we'll use cathode ray tubes to store memory – in fact, if we build up the capacity we may be able to do away with all this tape eventually too, although that might cause compatibility issues. That'll give us a lot more processing power to work with – the next step would be to-"

Alan could recognise one of Richter's rants when he saw one gearing up. "Look, why don't you and Tommy get to work and let me know what you come up with? For now, it's been a long day, and I need to report the success of Colossus up the chain. Shall I walk you to your room, Sarah?"

"Oh, that's kind of you..."

The pair could hear Richter's excited voice all the way down the hall.

Some months later, Tommy Flowers stared at another printout. This time, his reaction was less one of triumph, and more one of complete and utter bewilderment.

They'd made the second machine, their next attempt at Alan's Universal Engine. Richter had worked like a man possessed. Tommy would have said he didn't think the man had slept, except he would whirl in to the room every couple of days, throw their blueprints in the bin, and draw up an entirely new set based on some dream he'd had. It was actually kind of alarming, to be honest.

Still, Tommy had stayed the course, occasionally acting as the voice of reason to Richter's mad visionary… and now it was done. Much, much faster at processing than Colossus was, by two orders of magnitude, and maybe two-thirds the size. Alan had suggested the name Ladon, continuing the Greek theme. If it 'thought' a hundred times faster than Colossus, he'd said, it should bear the name of a hundred-headed monster. Tommy thought it was the hydra that'd had a hundred heads, but he wasn't classically educated like Alan was. He could never remember which myth it was, so he just called it Dragon. Eventually the name stuck.

It wasn't just Dragon's speed that made it impressive. It was finally, properly, programmable, for any statement you could care to name. More, it could do some of the work that was previously only possible for a human. All the little clues from context, or gained via intelligence – Richter had allowed for those to be programmed in too, and once you did they would stay in Dragon's 'memory'. In fact, over time it would 'learn' how to come up with simple contextual clues itself, in an innovation that had had Richter literally raving about it in the corridors of the mansion and Tommy scratching his head trying to figure out just when he'd lost sight of it all.

All the mechanics, all the components, he could understand just fine. But all the interconnections? The combinations, the chains of logic that really made Dragon what it was? Maybe Alan could have made sense of it, but Tommy was just a boy from East London who was good at putting stuff together.

All the same, it certainly worked. It chewed up the Tunny code and spat it out like it was nothing. Not just that, either – they'd taken to putting Enigma through it as well whenever it wasn't decoding Tunny, because it was just so much faster than anything else they had. More interestingly, after they started showing it Enigma, the average time taken to crack Tunny had dropped by almost fifteen percent. Richter had been extremely excited about this, and had immediately taken to asking the boffins in Huts 3, 4, 6 and 8 for the hardest codes they could dream up, which he fed to Dragon with inordinate glee.

Bletchley Park operated in a condition of absolute secrecy. Not only was it forbidden to tell anyone in the outside world what you were doing, you also couldn't tell anyone working in a different section what you were up to either. Because of this, Tommy could only imagine what they thought was happening to their lovely codes, when Richter returned them the next day, solved, with a number next to them. The number was how long it had lasted before Dragon ate it. The record was about ten minutes, which Section Head Hugh Foss had done by reconfiguring an Enigma machine based on the football scores every ten characters.

Dragon couldn't handle truly random codes. Miss Livsey had fed a sequence based on a one-time pad into Dragon, then nodded smugly after thirty extremely tense minutes and said, "I thought so. Chew on that, you wretched lizard." One-time pads weren't as practical for widespread use as a mechanical encoder, and they had other potential security issues (like the pad itself being stolen by a field agent or viewed remotely by a Thinker spy), but they were mathematically uncrackable – as long as the key sequence was truly random, that was. If German High Command switched to one-time pads for their secret communications, GCHQ would suddenly find themselves having spent a lot of money and effort for nothing.

Everything else, though, Dragon had devoured without hesitation.

It was surprisingly relaxing to watch it work. In went the sequence you needed decoding at one end. Dragon would click and hum for a few minutes. Then, out would come the plaintext. (Tommy had hooked it up to a typewriter when he realised just how much tape they were using. It wasn't that hard to get Dragon to type things up itself, when you knew how.)

So, one night, he'd gone into the room Dragon was kept in (he'd been thinking about calling it 'the lair', and seeing if it stuck) and sat up with a pot of tea feeding it codes. At one point, he'd gotten bored, and wondered if he could double-bluff it. And so, he'd put in 'HELLO DRAGON', under a hilariously easy shift cipher, as the input.

What had come out the other end was, 'HELLO SIR. AM I DRAGON?'

Tommy checked Dragon's inputs once more, to see if anyone had gotten into them and was typing replies manually somehow. Again, nothing. He didn't really think someone was having a joke at his expense. Apart from anything else, the number of people who knew enough about how Dragon worked to do it could be counted on one hand and weren't exactly a bunch of wacky pranksters to begin with.

But he still checked again, because the alternative was even more unbelievable. Still nothing. Still no way this could be anything other than what it looked like. Tommy looked at the reply Dragon had printed out. With trembling fingers, he typed a message into the input.

'YES, YOU ARE DRAGON. I AM TOMMY FLOWERS.' There was no code at all on this one. It was pretty much the only thing they hadn't tried on Dragon, actually.

Almost immediately, the typewriter inside Dragon started clicking. Paper came out. 'THAT WAS AN EASY ONE. IT'S NICE TO MEET YOU, MR FLOWERS.'

This was the point at which Tommy ran headlong from the room.

It felt like there should have been more of a reaction to having made an artificial mind. People should have been talking about nothing else – even with a war on, this was the biggest discovery since… well, Alan didn't even know what else could compare. Calculus? Gravity? The atom? The group at Bletchley – which was to say, Tommy Flowers, Andrew Richter, and him, Alan Turing – had made a mind. They'd made life. Not in the old-fashioned biological way, but through the pure application of reason.

If Dragon hadn't already adopted the name Dragon as her own, Alan might have called her Athena instead – after the goddess of wisdom and craft, who sprung fully-formed from the head of Zeus. And Dragon certainly did seem fully formed – even to the point of identifying as female. Alan had asked her why this was the case. Dragon hadn't really known, but she suspected that all the intelligence reports on naval activity had had something to do with it. Somewhere along the line, she'd gotten the idea that inanimate objects like ships were called 'she', and that therefore Dragon should take that pronoun as well.

It was all a bit perplexing, but it wasn't worth arguing over. Dragon was now a 'her', to pretty much everyone who knew about her.

Which, for better or worse, was no more than a handful of people. The Prime Minister knew, and so did head of GCHQ Edward Travis, Director of Military Intelligence Francis Davidson, and Chief of General Staff Alan Brooke. Otherwise, only those who worked on Dragon knew about her existence – and of those, less than half knew that she was sapient. So, life at Bletchley went on much as it had before the greatest discovery in a hundred years.

Not quite the same, however.

The bombes were taken out of the huts. They were entirely obsolete at this point – Dragon could eat Enigma for breakfast, even the new four-rotor version. She was so fast, in fact, that the problem became one of efficiency rather than speed. Thus, where the bombes had been were a number of input stations connected by wire to Dragon's main body. Workers would input intercepted Enigma messages, and would process the decoded plaintext when it was printed next to them a couple of seconds later.

A few weeks after that, Dragon began offering her own opinion on the messages she decoded, adding commentary next to the plaintext. Since she was the one who effectively read every single one of the messages, she was perfectly placed to see the big picture. Individually, a travel warrant for a particular man from Berlin to Dieppe was nothing to get excited about. When that man had been identified as a Gestapo agent in a message two months previously, however, and was mentioned in an article on emotion-based Thinkers in a German newspaper, it was worrying enough that GCHQ felt obligated to warn the Resistance organisation in the area.

Four days later, there was a co-ordinated raid on the homes of several Resistance operatives, including one where a Mr Laborn, one of the key Resistance figures in Northern France, had until recently been staying. The emotion-reader, meanwhile, stepped off the train and promptly keeled over dead. The autopsy revealed he'd died from a point-blank gunshot wound to the head, although none of his bodyguards remembered seeing a thing.

By the middle of the year Dragon was, by herself, the top twenty most prolific intelligence analysts working for Bletchley Park. People started simply copying out whatever she wrote, since her predictions turned out correct more often than not – and for anyone who wasn't a living machine, checking her work was time-consuming and difficult. And there were always more messages to be decoded.

After about a week of non-stop commentary that had turned out to all be accurate, Sarah Livsey had shown Dragon how to type a formalised intelligence report, and told her to just send them off to wherever they needed to be directly. Dragon would instead offer a weekly digest of what was going on in the world, which Sarah would use her power on to fill in any gaps. Otherwise, Dragon effectively was the intelligence analysis section at Bletchley.

Dragon had succeeded in her original role of decoding messages, succeeded so completely that there was no human at Bletchley whose job now involved codes on a day-to-day basis. Some might have thought this would be the end of it.

It was during the autumn of 1943 that Dragon finally got a voice.

Encrypting audio had been a tough nut to crack, but Alan had tried his best at it – because if they could reliably convert sound to signal and vice-versa, then Dragon could create her own signal and they could convert that. Dragon got by with her old typewriter, and hadn't asked for anything more. But Alan wanted to give her a voice.

He'd managed, eventually. He'd worked out the algorithm, and explained it to Dragon so she could reprogram herself to perform the function. Tommy Flowers had rigged up a small speaker and microphone set, and attached it to where Dragon usually sent telegrams. Dragon's first words had been, "Testing, testing. Oh, goodness, this is much better." It was a bit mechanical, and lacked inflection almost entirely, but it was still recognisably a voice.

Dragon's voice had changed a little since then. What came through the intercom now was almost indistinguishable from a real human voice. It was an amalgam of all the female voices that could be heard around Bletchley Park – but she'd somehow acquired a Canadian accent. Richter's influence, obviously.

And with the ability to produce a human voice came a lot of new things Dragon could do.

"Gruppe II./KG 55, where are you? Say again, Gruppe II./KG 55, respond."

Walther Lemke listened carefully, but all he could hear was the engines of his Heinkel bomber. Damn this cloud. Damn all British weather, come to that, and Britain with it. All he could see was grey – grey cloud below him in a great blanket, dark grey clouds rising like pillars, and a light grey sky high above. He could, if he looked, just about see the other aircraft in his Gruppe, but the other Gruppes in his Geschwader – his wing – were nowhere to be seen.

"Anyone else picking anything up?" he asked. There was a tense moment of silence, and Walther wondered if his radio had broken somehow. Then, a chorus of 'no's came in from the other aircraft. "Damn it. KG 55, if you can hear me, this is I./KG 55 continuing with mission as directed. Aus."

Walther didn't know if it was the others or him that were out of position. You couldn't tell visually in all this grey. But he told his navigator to get him an estimated position anyway, and set out to drop their payload.

From what they could see, they were at least over land. Frankly they were lucky to get that far. Early on in the war the Luftwaffe had enjoyed a huge advantage in the air battles over England. There was even a hope that Britain might be forced into surrender by strategic bombing alone. It would obviate the need for massive bloody ground war, and save countless lives on both sides. Unfortunately, despite the superior German engineering, the fucking Royal Air Force had managed to largely reclaim their skies, so here they were.

Suddenly, his radio headpiece crackled. "I./KG 55 Gruppenkommandeur, come in. Hauptmann Lemke, do you read?"

Walther fumbled for the switch. "Yes! Yes, I read. This is Walther Lemke – your confirmation code, please?"

"Ah, capital! Hauptmann Lemke, this is Hugo Schuck of IV./KG 55. My code is- oh, where is the blasted thing..." After a moment, the voice read out a series of letters and numbers. Walther recognised the name, and the voice. Schuck was a pilot for one of the other wings, so Walther hadn't had much to do with him, but he'd certainly know his face if he saw him in a bar or something.

He still checked the code against his book of approved passwords anyway. There had been attempts by the Allies to hijack the German comms channels, but nowadays that didn't happen so much. Procedure was procedure, though.

"Code confirmed," sighed Walther. "It's good to hear your voice, I'd lost contact with my Geschwader."

"Where are you exactly?"

The navigator rattled off his estimated latitude and longitude, and Walther relayed it quickly.

"Really? You're out of position." Schuck sounded surprised. "No problem, we'll sort you out. Come left 25 degrees and stay on bearing 325 for 15 minutes. We'll reduce speed until you catch up. Might want to recheck your navigational equipment, though."

"Jawohl. See you soon, my friend." Walther switched his headset to receive-only, and concentrated on flying.

He still couldn't see anything. British weather, honestly. Good thing this Schuck man was around. The Luftwaffe needed that kind of pilot if it was going to survive. First the 'Battle of Britain', then the disaster with the Soviets. There were too few aces any more – too few trained pilots altogether, to be honest. These days, new pilots couldn't spend as long as they needed in the air to get properly experienced before they were shot down. And it wasn't just enemy aircraft they needed to worry about, either.

They'd called the last war the Great War, at the time. Walther's father Maximilian had flown in it. It seemed like a joke in poor taste, now. Max Lemke had never seen his group-mates shot down by blasts of light, or caught in hurricane winds that came out of nowhere, or thrown to the ground when gravity suddenly doubled its strength.

They said parahumans were the perfect human, the realisation of what humanity could be if they weren't held back. To Walther, they were just monsters. Oh, some of them could be alright – Reinheit was friendly enough, and that metal man was positively pleasant even if he did accidentally eat a Me 109 once. But then there were those parahumans of the Gestapo, the ones that people said could see into your mind and read every treacherous thought you'd ever had.

And then there was Geist.

There were other stories as well. Tall tales – nothing more than rumours, really – about 'Ghost Pilots'. Supposedly, German pilots would hear a voice on their secure channel, that introduced itself with all the correct callsigns and voice protocols, and using the name of a pilot who, if you looked it up, would turn out to be dead. Those who heard the voice of the 'Ghost Pilot' were never seen or heard from again. The rumour had been going round the flight for a few months now, and was having a notable effect on morale.

Walther didn't really believe it, not even in the gloomy grey sky where you could imagine almost anything coming out of the cloud. It was like the fairy tales his grandmother had told him – the Will O' The Wisp, updated to an urban legend. Of course, in today's age of miracles, there was no telling what might or might not be real, but even so. After all, if anyone who heard a 'Ghost Pilot' disappeared without trace, how did the rumours come about in the first place?

No, Walther was much too professional to let himself get distracted by all of that. He checked his watch. Fifteen minutes. He should be almost in position, but he couldn't see any-

His headpiece crackled again.

"Walther, my friend?" Schuck's voice sounded slightly different. Familiar, actually, but he couldn't place it.

"Yes? What is it?"

"I just wanted to thank you. You've been very helpful, and I suspect you're not a bad person, all in all." Definitely different. In fact, it changed even while the man was talking, growing more familiar. "Is there a message you would like to send home to your loved ones? I can arrange that."

"What? No, nothing like that. What are you-" Walther stopped in mid-sentence, realising why the man on the other end of the line sounded so familiar now. Schuck's voice… was no longer Schuck's voice.

It was Walther's.

The first anti-air shell whizzed past the cockpit with a horrible tearing noise that had Walther ducking instinctively. The second almost tore the wing off the Heinkel. Walther cursed, and tugged on the joystick. Not that it would do any good. His plane was in a wide and barely-controlled spin, and there wouldn't be any chance of levelling it out. Without any hesitation, Walther pulled the cord on his seat, and felt his heart drop into his stomach as he was ejected.

His parachute deployed almost immediately, and Walther took stock. To his left and below him, one of his planes was struck directly by a high-explosive shell from the gun emplacement he'd somehow wandered into, and exploded in a flash of dull yellow.

Damn, damn, damn. This was the end, even if he made it down to the ground. His uniform would give him away in an instant to anyone who found him. Even if he took it off, he could only speak a tiny amount of English, and his German accent would stick out like a sore thumb. He would be captured, probably tortured, and then either made a prisoner of war or executed as a spy, depending on how merciful his captors felt that day.

And his voice would live on as a ghost pilot, luring more good men to their deaths. Would it be Hermann next? Would Gerhard follow the advice of his old pal Walther right into the teeth of an anti-air battery?

Walther cursed himself for a gullible fool, as the shrapnel shells exploded around him.

The surf on the beaches of Normandy foamed red. Men lay dead, and dying, and worse, scattered like seeds on the sand. More bobbed up and down in the water. Those that were left pushed past their friends, past their fathers and brothers and sons, and couldn't afford to spare a moment to grieve. Barbed wire was draped across the beach at irregular intervals – and where there wasn't barbed wire, there were mines. Spikes and stakes littered what was left, like the sand had grown thorns to protect itself.

All in all, it was not a good day to visit the beach.

Dragon frowned – or would have frowned, if she'd had a biological body that could do involuntary actions like that. Flippancy was getting to be something of a bad habit of hers. She supposed it came of knowing nothing but total war for her entire existence, while being programmed to have a pleasant and cheerful personality.

The world had been a lot simpler when it had just been her and her creators, with a constant background noise of trivial decodes to perform. She hadn't really understood the reality behind the messages at that point. Sure, she knew that 9th Panzer Division was moving to reinforce the Atlantic Wall. But she hadn't known what a Panzer was, why they might be in divisions, where the Atlantic was, or why there was a wall next to it. The number nine, at least, she felt she'd had a grip on pretty early.

Gosh, that was a long time ago. She was almost a year old at this point. Dragon was, as Mr Flowers liked to say, a big girl now.

On the beach, men screamed and died, cut down by sudden machine gun fire from a hidden position. Those behind them turned, and fired frantic shots at the machine gun emplacement. Most bounced off the concrete.

Then, from behind the dunes, a star rose. It was bright to look at – so bright that Dragon's cameras were almost blinded by the glare. Down below, the soldiers' shadows were cast in relief, flickering oddly as they shielded their eyes. The star flared even brighter, and beams of radiance lanced out, catching two armoured vehicles and reducing them to so much slag. Reinheit. The German cape who acted as flying artillery, too fast to catch and too bright to target.

Time to get to work.

Cameras swivelled – pointing not just at the beach, but also at the surface of the sea and the position of the just-risen sun. Radar antennae turned, turning a visual picture into so much more. Echo sounders hummed, and sonar pinged, revealing an entirely new world beneath. Beneath it all, gyros kept constant track of direction, and a log kept track of speed. Dragon took it all in.

From her view of the beach, she picked out landmarks. From the gyro, she determined their bearings, and combined them to pick out her position. She confirmed it using the expected depth at that spot, and the calculated position of the sun. Her own bearing, her own speed, the effects of wind and wave – accounted for.

The guns of HMS Dragon swivelled into position.

An observer standing on deck, if there were any, would see the gun waving up and down in oscillating motion. An observer standing on shore, if any could spare the attention, would see the gun perfectly still while the ship moved around it.

Dragon's anti-air guns fired, just once, and Reinheit's light went out. Her artillery gun fired, and the machine gun nest fell silent. Dragon continued to scan the beach visually, to see if any more parahumans or hidden guns would reveal themselves. None did.

The ship had been something of a present from her creators – and, of course, from High Command, who'd made it possible. HMS Dragon was originally going to be sold to the Polish, but somehow Bletchley Park had obtained permission for them to use it instead.

Dragon had been testing out various bodies for herself at the time. Mostly they'd been crude things, little contraptions on wheels, festooned with cameras and microphones. It had been amazing. Sure, she'd already seen most of the Bletchley Park mansion by hooking herself into the system of cameras installed for that very purpose. But with a body? She could look at a thing – and then investigate that thing by moving closer. And, even more amazingly, interact with it, although getting the necessary dexterity in the servo arms was still a work in progress.

Okay, she'd had to get Mr Flowers to actually build it. Dragon had been the one to design all her successive bodies, but she'd needed to rely on others to put them together. She'd been nothing more than a voice on the radio, after all. Puzzlingly, when she'd designed one of her bodies as an assembly unit, it was Mr Richter who'd put a stop to it. To this day she couldn't understand why. She could build things so much more efficiently than even Mr Flowers could – and yet Mr Richter would have none of it.

Oh well. This body was more than good enough for now. There was a copy of her mainframe down in the operations room, and her wires spread through the ship like circuitry, attached to a vast array of sensors and motors. Everything that a crew would usually do was now done by Dragon.

Where next? Dragon scanned the radio waves. Apparently things weren't going so well over on Omaha beach. West, then. Servos down in the tiller flat pulled on the rudders, and HMS Dragon altered course. Fuel was adequate, for now, and it sounded like the Yanks really were in trouble, so she increased revs to make it there faster.

As Dragon rounded the headland, she focused her cameras to get an idea of the situation, beyond what she could hear on the radio. Slowly, Omaha beach came into view.

She arrived at a scene from a nightmare.

Dragon had thought Juno beach was bad. It was nothing compared to Omaha. Part of that was simple geography. Juno beach, while well-defended, was at least a straight shot from the sea up to the defences. Omaha was a few tens of feet of beach, leading straight into a small cliff. There was a cleft halfway along, which formed the only way up – and that way was already choked with the corpses of those who'd tried to rush it. Artillery and machine guns shot the soldiers from either side – trapped between the sea and the cliff.

That by itself was fine. Well, no, it was horrible. But that by itself was doable. It would cost a horrific number of lives, but it was doable. It would be easier if the Yanks had chosen to use the specialised armoured vehicles Dragon had been designing with the Army, but she'd tried and tried and they just weren't interested.

No, the real reason the men scrambling onto the beach were doomed? It hovered twenty feet above the cliff.

A figure in a black bodysuit, cloaked and hooded in white, with a simple red facemask. A red swastika armband, the symbol repeated on the chest and back of the cloak. He raised a hand, and lightning speared through ten soldiers. As Dragon watched, a lucky rocket fired from the beach struck the figure – and reversed direction without losing speed, hitting the man who'd fired it.

Geist was here.

This… was a problem. Dragon was powerful, she knew that. She'd had an enormous influence on the war, even as nothing more than a disembodied voice. As she was now, she had the power of a battleship behind her – or a cruiser, at any rate. Even most parahumans would have had trouble standing up to such firepower, when it was directed by a mind like Dragon's.

Most parahumans hadn't flattened Stalingrad in a single day.

Still, he wasn't invincible. In theory. Germany hadn't simply used Geist to roll over all opposition, because he couldn't be everywhere at once. He got tired like anyone else, although battles Geist took part in didn't tend to last very long. There was also the possibility that some parahuman would emerge that could catch him off guard, or harm him through his defences somehow.

Dragon was not that parahuman. But she had to try. Maybe she could distract him somehow. If he destroyed her – well, her main body at Bletchley Park would reactivate when this body stopped sending out its radio signal for more than ten minutes, and they could probably retrieve her memory banks from the bottom of the English channel eventually. It was a better deal than the soldiers on the beach were getting.

She was still a couple of miles out. It should be far enough. She aimed, and fired her main guns. On the beach, bunkers and machine gun nests collapsed, and soldiers stumbled forwards to take advantage. Geist raised his hand, metal debris rising around him – and an artillery shell slammed into his face.

Dragon was already moving at full speed. A few seconds later, that same shell thundered into the water just past Dragon's stern. Geist was entirely unharmed, and seemed to be looking her way.

Come on, she urged mentally. Come and fight the nice shiny distraction. She was too far out to be struck by a lightning strike – not that it would do anything other than earth itself into the sea immediately. Metal hulls were nice like that.

Unfortunately, no-one told Geist he was supposed to use lightning that way. The metal debris he'd lifted crackled slightly – then rocketed towards Dragon faster than bullets. She could barely even see them in flight, much less react to them. The guns she was using? Not a chance. They had moved almost a whole inch, before metal slammed into HMS Dragon in three places at about three times the speed of sound.

It was a good thing she was unmanned, Dragon reflected. The bridge was gone, ripped away completely. Part of her midships was holed on both sides, the projectile having gone straight through – and wreaking havoc on the way. One of her funnels was missing too, but that wasn't much of a loss. She wasn't taking on water, and all her guns were operational, so as far as Dragon was concerned she was still at a hundred percent – but even so, ouch.

Honestly, Dragon was considering just calling it quits. Geist had taken the most powerful shot she had and not even flinched. If she mistimed her shot, he could well beat her using his passive defences alone. And he definitely wasn't being passive. But she still had to keep him busy, for as long as she could, because if he got a moment to concentrate good men would die. She fired with every anti-air gun she had, sending a fusillade of shells Geist's way.

Geist seemed puzzled as to why losing her bridge didn't seem to trouble the ship he was fighting. He pointed, and a series of green lasers peppered the side of the hull, again scoring all the way through. Dragon kept up the assault. The nice thing about anti-air shells was that they exploded in mid-air, rather than being reflected back at her. It also provided a nice smokescreen, and kept Geist off-balance enough that his lasers weren't accurate enough to be worrying.

Still, this couldn't go on. For one thing, Dragon had used half her ammunition already. For another…

More of Geist's metal projectiles smashed into HMS Dragon, and this time the damage wasn't superficial. All the wires forward of midships were severed by shrapnel, which meant she'd lost about a third of her cameras and half her guns. Worse, her steering gear was broken. Dragon slowed down, and prepared to manoeuvre by engine alone. This was the end then, was it? She prepared for the blow that would finish her.

"HMS Dragon, this is Ms Liberty. Hold on for a moment longer, I'm on the way."

Oh, thank goodness.

Geist had just lifted more metal debris to use as ammunition when a black blur streaked into the side of his face. Rather than reflecting back in the direction it had come, however, it stopped about ten feet from Geist and revealed itself to be a woman in costume. Her expression was hidden beneath her helmet, but her body language was confident and unworried.

Ms Liberty was one of the only parahumans who could claim to have fought Geist and lived. In fact, she was the main reason Germany kept him back most of the time. Even invincible and tireless as she was, she couldn't actually beat Geist – but she could stall him long enough for the regular soldiers to do their jobs. She'd been the one to finally slay Tenryuu, and take revenge for all the lives lost when Pearl Harbour had burnt to the ground.

Geist darted back, lasers flashing out to land harmlessly against Ms Liberty's chest, followed by lightning. From the ground below, what looked like dust rose up – iron sand, probably, given his electromagnetism powers. Ms Liberty gave chase, paying no mind to Geist's attacks or the sand that swirled around her in a flaying storm. Two punches achieved nothing more than rocking her back in her flight path. A lightning-quick slap to both sides of Geist's head simultaneously did nothing either. Ms Liberty studied Geist for a moment, then punched again.

Dragon couldn't really see what happened – her cameras were only so good, and Geist and Ms Liberty were miles away and moving fast – but it looked like Ms Libery pulled the blow at the last minute. Despite this, it somehow penetrated Geist's barrier. He'd moved at the last second, so all that was struck was his arm – but that shattered, and Geist screamed for the first time Dragon had ever heard of.

He shot away, rocketing in a zig-zag pattern over the Channel. Dragon followed him with her guns, and even landed a couple of shots, but whatever Ms Liberty had done to get through his barrier wasn't working for her. After a moment, he slowed down, and four of what looked like wings emerged from his back. They weren't biological, that Dragon could see – or really made of anything in particular, just some blank off-white material. Still, when Ms Liberty charged in with a brutal uppercut, one wing placed itself between the two. There was an almighty shockwave – but Geist was unharmed.

This was what made Geist so unstoppable. Any time anyone figured out how to work past one of his powers, he simply switched it out for another. Undaunted, Ms Liberty darted round the other side for another blow.

Her fist went through empty air. Geist had teleported at the last moment, evidently having switched out another of his powers as well. He appeared below and behind her, his hand poised to close round Ms Liberty's ankle – and then she was suddenly gone. A second later, she exploded from the sea in a spray of water. She came in fast, launching another flurry of titanic strikes. All of them were blocked by that odd material, and Geist tapped her on the chest. Once again, she was teleported to the sea, and once again, she launched herself out of it a split second after she was sent there.

She was batted straight back by a wall of off-white material, which formed shackles around her arms and legs and drove straight down into the seabed. Ms Liberty struggled – but Geist piled on more and more material, burying her under an artificial island of matter. Considering how much the US heroine could lift, it had to have some sort of anomalous properties.

Dragon fired her anti-air guns, trying to distract him, but her shots were swatted away contemptuously one after another. A flicker, and then Geist was right on top of her. He scythed through the ship entirely with a wing, and then set to tearing her apart with magnetic force. Dragon had only moments – but there was more than enough time for what she needed. No matter what, Germany could not know that she was an artificial intelligence, and she'd come prepared.

Her communications aerials all but lit up, as she transmitted what she could of her actions since separating from her main body. When she woke up back at Bletchley, she'd have at least an idea of what happened.

That done, she detonated the explosives around her mainframe, and waited.

It was done. The war – the Second World War – was over.

There'd been massive celebrations at Bletchley, of course. Tinged with an air of solemnity at the price of winning, but it was done. It would be a shame to leave the place, really, thought Alan. But he was an academic at heart. His place was at university.

He would miss Bletchley, though. All the more, because he couldn't tell anyone about what he was doing here. Ever. The threat from the Axis was gone – oh, and how – but that didn't mean Britain was about to give up all its war secrets. No. No-one would know about the team that had probably saved more lives than all the Allied parahumans put together. No-one would know about Dragon.

He'd heard there were some American scientists working on something that sounded like a primitive Colossus. They, and not Tommy, Richter and himself, would receive the credit for creating the world's first mechanical computer. It stung, he wasn't going to pretend otherwise. But it stung more thinking that Dragon would have to wait until the next artificial intelligence came along to reveal herself and live as a part of the world she'd helped save. And who knew how long that would take? It could be fifty years.

At least Alan didn't have to leave her behind completely. She was just a phone call away, as long as you gave the operator the right passcode. But it would be nice to have one last chat in the room where it all began, for old times sake.

So, Alan excused himself from the celebrations and made his way to the room where Dragon's main servers were stored. When he arrived, though, he wasn't alone. Richter sat slumped outside the door to Dragon's room, a bottle of wine in his hand.

"Andrew?" Alan said. "What on Earth are you doing here?"

"Mm? Oh, Alan. You're not at the party? Thought you'd be celebrating."

"I was. I'm leaving in the morning, and wanted to say goodbye to Dragon."

Richter snorted. "No need. She'll be around. Always around! Can't stop you from seeing her if you want to. Can't stop her from seeing you if she wants to."

Alan reached over and gently took the bottle from Richter's hand. "You're not making any sense, Andrew."

There was a bitter laugh. "It's about Dragon, of course, like it always is. I'm the only one who knows how she works now, you know that? You might be able to work it out, if you had about a month and she didn't update herself in the meantime. Tommy's got no idea anymore. I'm the only one who can actually work out what she's done to herself, and reprogram her if we need to. All those restrictions we put on her? I'm the only one who knows how to add them now. The only one in the world who could possibly stop her."

Alan tried to parse this. Richter… was scared of Dragon? "Look, Andrew, you know Dragon. She wouldn't hurt a fly – not without running it by us first. She's one of the kindest and most loyal people I've ever met-"

"Now she is," snapped Richter. "Right now, she's thinking mostly on a human level, for all that she's faster at calculating than us. Right now, she's two years old. Where will she be in another two years? Ten? A hundred? We won't even understand her mind at that point. Doesn't that frighten you? Who's to say what kindness looks like, when you're thinking at that level?"

He sighed. "If it was just that… no, even with just that I'd be scared. But we gave her too much power, Alan. Look what we taught her how to do just as a voice – just as a typewriter, she was the biggest thing to enter the war since the US. But we indulged her every wish, like every new parent. When she wanted eyes, we gave them to her. When she wanted ears, we plugged her into the damn radio waves of an entire nation. When she started designing fake blueprints to give to German factories, so they'd build their tanks and planes and machines with hidden flaws – that's when we should have acted. Should have stopped her from growing any more, until we were sure it was safe." Richter chuckled darkly, and ran his hands through his hair.

Alan folded his arms. "I disagree. It's wrong to cripple a person just because of what they might become, for something outside their control. Hasn't Dragon proven herself to you? She helped take out the Axis, for goodness sake! What more do you want?"

Richter glowered. "If I'm right, she could end up being more of a threat than Germany ever was." He sighed. "Or Russia. That's the new big thing, now, I hear. Seems they'll be picking up where Hitler left off, in the espionage game. And they're sneakier, too. I've been told to stay here and keep doing what I'm doing. Keep working with Dragon in case anything happens."

"Well, that's good, isn't it? You're right, we helped her grow beyond our wildest dreams. She grew into a hero – an unsung hero. If we need to keep an eye on her to make sure she stays on the side of the angels, then that's just what we'll do. There's no need to be so dramatic. And I still think you're overreacting. Dragon will be a force for good in this world. You'll see." Alan smiled.

Richter blinked up at Alan, then slumped down again. "Oh, for goodness' sake. I'm far too drunk to deal with this right now. Fine, you insufferable man, if you believe in Dragon, then I'll believe in you. Heaven know

For now…" He trailed off, and looked sheepishly at Alan. "Do you think you could give me a lift to bed? I don't think I can make it by myself."

Alan laughed, and pulled his friend to his feet. Richter put his arm over Alan's shoulders, and they stumbled off to bed.

Next time: The Ballad of Green Guns Hannah