"I spy, with my x-ray eye..."

"You don't have x-ray eyes."

"How do you know?"

"Because you don't," said Winfred, with the unwavering confidence of a child.

"Well, anyway," said the Doctor, "I spy with my eye that's interesting and special in some undefined way..."

"It's brown. You've got brown eyes."

"So have you."

She nodded. "Because of gin attics."

"Genetics. Gen. Eticks."

"Gin ethics."

"That'll do. Anyway, as I was saying, I spy something beginning with S."

Winifred stood up on the bench and looked round the park. "Grass."

"No. That doesn't begin with an S, does it?"

"You could have lied."

"I didn't. And sit down in case you fall."

She sat down again and kicked her feet back and forth. "Sandwiches."

"What sort of sandwiches?"

"Lettuce."

"We've only got cheese," he said, offering one.

"I don't want cheese."

"Alright. It's not the right answer anyway."

"Spoons."

"Where?"

"I don't know," she shrugged.

"It's something in the park. That's the point of the game, isn't it?"

"I give up."

"Already?"

"Yes."

"It was 'starling'. That's a type of bird."

"Where is it?"

"It flew away."

Winifred frowned, "There's too many sorts of birds. Why do they have to have so many names?"

"So it doesn't get too repetitive when they get used in poem and prose. People like the imagery, they go on a lot about how birds are free, but really it's just that they can fly. I expect birds look down and think about how free they'd be if they knew how to make bread and if they didn't have to worry about cats. People think 'oh, birds aren't trapped on the Earth', but they are, they still need gravity and an atmosphere. And it wasn't birds who landed on the moon. Not first, anyway."

"That was America," said Winifred.

"Clever girl."

"I don't like birds anyway."

"Why not?"

"They've got little eyes. They look like they're dead but they move. And they have big flappy arms." She flapped her own arms to illustrate the point. "And then sometimes you see one in the road and it's all flat and people won't let you look at it. You do, but not other people."

The Doctor nodded. "Other people are strange, aren't they?"

Something squawked above them and they looked up in time to see a large black bird slamming into the ground in front of the bench.

Winifred got up and poked at it with her foot. "It isn't flat," she said in a solemn and big-eyed way. "It's a bit flat, but it doesn't have car shapes on it."

"Maybe it was sick," he said taking her hand.

"We could take it home," she said.

"Nah, your mum wouldn't like that."

"She might. We could say it was a present."

"That's not a very good present, is it? How would you like it if you got a dead bird for Christmas?"

Winifred thought about this for a moment. "I wouldn't mind."

"You're a bit morbid," he said, laughing too quickly. "Anyway, that'd be doing a cat out of a good meal."

Winifred tugged on his hand and he followed her gaze up to a small flock of pigeons flying round and round in a tight circle, birds occasionally falling away and rejoining the formation.

"I didn't know they did that."

"I think we should go home," he said.

--

"...and so she was related to the Vikings too, because," he paused for effect, "the baby was her mother."

"I knew that," said Winifred.

"No you didn't."

"I did. Children are never in stories about grown-ups unless they're important. Like when that little boy turned people into zombies, or when that girl was a battle computer."

"You're in my stories," he protested. "The ones I tell other people. I'm always saying how clever you are."

"I must be important then."

"You are. You're very important."

"More important than the Prime Minister?"

"There's been lots of Prime Ministers, but there's only one of you. That makes you much more important." He tried not to see her as something ephemeral, something that could be missed entirely with the ill-timed flutter of an eyelid. She was small and fragile and things like that were never really safe.

He tucked the covers round her, "Important people need their sleep," he said, switching off the lamp by her bed.

"Can we go to the park tomorrow?" she asked when reached the door.

She looked so pale and tiny in the light spilling in from the hallway, and for a moment he could see her lifeless. His heart skipped a beat, but when he tried to say 'No' it came out as "We'll see what the weather's like."

--

The light was huge and terrifying and burning into his brain. He could feel his pupils trying to close completely and a slight pressure on his face that moved like a thick and clammy spider. Something terrible and deadly was trying to drown him in light, burn out his mind, trying to evaporate him.

"It's sunny," said Winifred, holding his eyelids open with small but efficient fingers.

He batted her hands away gently and rubbed at his eyes. "What?"

"You said we'd go to the park if the weather was nice and it is so can we go to the park I put my coat on and everything."

"You and I need to have a long talk about punctuation someday," he said sleepily.

"Please," she added, apparently as an afterthought.

He checked the alarm clock and sighed. "It's eight in the morning. On a Sunday." He did have to respect the dedication of a child who would wake up so early, check the weather, get dressed, and then try to wake her parents with the power of sunlight. It was still annoying though. "Go back to sleep."

Winifred shook her head, "Don't want to. You said we could go to the park."

"It's closed," he lied.

"Why's it closed?"

"It just is."

Winifred looked doubtful. "How do you know it's closed?"

"Because it is," he said. This was getting increasingly irritating. Dealing with children on a full-time basis might indeed be enough to drive people to insanity. Or at least to appearance of such, like when they wandered off in a department store and you were left there talking to yourself while they got involved in some inadvertent shoplifting. Rose stirred beside him and interrupted this train of thought. "And now you've woken your mother," he added.

"Why's she got her coat on?" asked Rose.

"We're going to the park," said Winifred.

"No, we're not," he insisted.

Rose poked him in the shoulder. "Did you say you'd take her to the park?"

"Yes," said Winifred, "he did say that." She widened her eyes in a suspiciously manipulative fashion. "Now he says it's closed."

"You promised her," said Rose. "Look how upset she is."

The Doctor stared at the ceiling and thought about the consequences of telling his wife that there might in fact be something alien and dangerous at the park. Based on the evidence of a few birds acting strangely. When she thought he was just trying to find an excuse to go back to sleep. The most sensible course of action probably was to mention his suspicions, but he got the feeling that she'd be incredibly angry if everything turned out to be perfectly normal and terrestrial. Which was entirely feasible. "It's eight in the morning," he managed.

"So it'll be nice and quiet, won't it?" Rose nodded at Winifred. "You go and watch the telly for a while and Iyou/i get dressed and take her to the park."

Winifred skipped away cheerfully and the Doctor admitted defeat.

--

The park was indeed closed. Closed, sealed, and cordoned off. The birds still circling, a larger flock now, casting a dark shape against the sky. A small number of army vehicles blocked the street at either end, soldiers milling about and waving people away. Someone had put barricades up around the park itself and there were two police cars, a fire engine and, bizarrely, an ice-cream van, which presumably had turned up for the weekend outings and stayed for the public sector consumers.

The Doctor wondered how to get past the cordon and whether trying to was necessarily a good idea. This was, after all, the sort of thing he'd decided to take as a sign that he should take Winifred home and forget the whole thing. He could just let it be someone else's problem and then read about it in the paper once it was sorted out. Though he was fairly certain that what was actually going to appear in the newspaper wasn't going to be remotely true. He knew that he'd missed an awful lot of interesting events in the past five years, and he found it almost impossible to just go with the entirely sensible instinct to walk away from this one.

"Ah, Mr Foreman. I was wondering when you'd put in an appearance." The Doctor turned and saw Robin Collins walking towards them. Which made him even less willing to miss out on whatever was happening here. "And this must be little Winifred. Growing up fast, isn't she?"

"What's in the park, Mr Collins?"

"Unexploded German bomb. Not the sort of thing one wants to leave lying around."

"That would explain the birds then. Seagulls in particular being known for their attraction to mysteriously forgotten World War Two munitions."

"Do you want to take a look? She can come," he added, nodding at Winifred. "It's quite safe, as long as you know what you're doing."

"That's Whitehall for 'can you help me?'" the Doctor told Winifred. "It's quite a simple language despite its apparent complexity. Native speakers tend to use at least three times as many words as they need to, which can be confusing for the learner. Luckily most of them can communicate quite well in English, though they often like to pretend that they can't."

Winifred looked at Collins with interest. "Will there be dead birds?" she asked.

"I think there's an owl," he said, carefully.

"Oh, really?" asked the Doctor. "Anything else interesting?"

"Just the birds."

The Doctor looked at what he felt was quite a respectable military presence. "All this for some birds? Bit of an over-reaction, isn't it?"

Collins raised an eyebrow, "This is an area we like to keep an eye on. Some of the locals are quite interesting."

"Are they really?" The Doctor covered his daughter's ears. "I do think Mrs Anscombe's up to something behind her wife's back. Not that I listen to gossip, mind," he added, giving Winifred her hearing back.

"Of course not. But are you interested in seeing what's in the park?"

"I've always been fascinated by imaginary leftovers from wars," said the Doctor, "so yes." He crouched in front of his daughter and looked at her seriously. "Winifred, I want you to stay close to me and don't touch anything and do ask questions. And if I tell you to run away, you do it. Understand?"

She nodded.

"Right," he said, standing up and taking her hand, "and when we get home we tell your mum we went to the library."

"Training her in the family business?" asked Collins.

"What, supermarkets?" He looked at his daughter. "What do you know about supermarkets, Winifred?"

"They bring happiness to many people," she recited, "and are a valuable part of our economy."

"Isn't she clever?" asked the Doctor, lifting her over the barricade and then jumping it to land next to her. "She knows all sort of things. Almost all of which are objectively true according to the modern understanding of the universe in which we find ourselves." He took her hand again. "I was thinking of teaching her French. Or German. Something European anyway."

"She's very advanced for her age," agreed Collins. "They say intelligence is a mix of environment and genetics. Which do you think is the more important in her case?"

"Oh, I expect she gets it from Rose. I didn't marry that woman for her looks, you know, although she is very beautiful as well. Winifred's got my eyes though, haven't you sweetheart?"

Winifred looked up at Collins and held an eye open with her free hand. "They're brown," she said.

They stopped in the middle of the park, standing in the dry grass and breathing warm summer air.

"There's something under the ground," said the Doctor. "It's been here quite a while, because the ground isn't disturbed. I imagine it's probably a bit older than that bomb you made up."

"What do you think it is?"

"Well, I don't think it crashed, or if it did it's fairly intact. Might be a survey vessel monitoring long-term trends. Might be a probe being recalled."

"Recalled?"

"Well, its engines are firing up."

Collins looked at him curiously, "How do you know that?"

The Doctor pointed up at the circling birds.

"Magnets," said Winifred, helpfully.

"Clever girl," said the Doctor. "Magnets, Mr Collins. A magnetic field, which is the sort of thing that helps in a gravity-drive. One step up from lighting the blue touch paper and crossing your fingers. And," he continued, warming to the subject and to the feeling of being the only person with any understanding of what was going on, "that confused the birds, because they use the Earth's magnetic field to work out where they're going." He was quite proud of that little monologue. He hoped there was more where that had come from.

"Wait," said Collins, "birds know about magnetic fields?"

The Doctor looked at him with the air of someone being confronted with incredible stupidity. "How did you think birds navigated? Did you think they had little maps that they hold in their little beaks and check every hundred miles?"

"They don't," said Winifred. "They use magnets."

"Anyway," he continued, "if you're in luck whatever's down there will just power up and fly off never to be seen again. Problem solved."

"And if luck's in short supply?"

"Have you ever read IWar of the Worlds/i?"

"I've seen the film."

"Which one?"

Collin shrugged. "It had Tom Cruise in it."

"Of course it did. The point being that it might not be all that benevolent. In which case you should probably come up with some sort of a plan since I do live round here and I'd hate to see the area trampled to bits by a massive alien death machine. Not that I think that's necessarily what'll happen, since I do know the difference between fiction and reality."

"Is there anyone in it?" asked Winifred, looking at the ground with fascination.

"Good question. If there is they're either very bored or in stasis."

"Like those dinosaur people," said Winifred.

"Exactly," said the Doctor. He noticed Collins giving him a concerned look. "What? It was years ago and it's not like anyone's likely to believe her anyway."

"You are aware of the Official Secrets Act, aren't you, Mr Foreman?"

"Yes, but I signed it with another name. And a different face. Signed it with different DNA, actually. The hypothetical question then being that if DNA counts and I've signed it does that mean she's half signed it? Does that mean she only has to keep half the official secrets? That one of her X chromosomes has security clearance?"

Collins sighed. "Shall we ignore this and return to the matter at hand?"

"Yes, we shall. You realise someone's going to have to go down there?"

"How?"

"You could try digging. Dig a big hole and see what you find. There might be a door on it or something. Probably will be, actually, if there's anyone inside it. That'd be how they got in."

"Can I dig?" asked Winifred.

"No, you can't."

"Why not?"

"You're too short. You can't go into alien spaceships until you're at least-" He stopped. "Can you hear something?"

A low rumbling sound started building up on itself until the ground shook slightly. A piercing shriek emerged alongside it, getting louder and more insistent.

"I think we should stop standing here," said the Doctor, picking up Winifred. They ran across grass and concrete, arriving at the barricades again as something huge and metal emerged from under the park. It lifted up and hovered, bits of earth and concrete falling from the top.

Then it fell, slamming back down into the ground.

The Doctor looked thoughtfully at what was left of the park. "Mr Collins, I need you to do something for me."

"What would that be?"

He handed Winifred to the man from Whitehall. "Take her home."

--

"I'm going to be sleeping on the couch for the next month or so, aren't I, Mr Collins?" said the Doctor, when Collins returned from his mission.

"Certain things were said that might seem to imply sanctions of some sort, yes."

He couldn't blame her. Not only had he gone looking for trouble, he'd taken Winifred with him, indulging the child's curiosity and hers as well. Find, investigate, interfere. Mirror. Signal. Manoeuvre. It was instinct that had never quite faded, like finding you could still swim after years on dry land.

He looked at the still metal disc lying in its crater and wanted to know everything about it.

"Its engines failed," he said. "If there's a hatch I can't see it. Probably just very well hidden. People do that sort of thing despite the obvious health and safety implications. Oh, and you're probably going to need another cover-story. This thing doesn't really look like it fell off the back of a Messerschmitt."

"Thanks."

"I'm not doing this for you," he said. "You merely happen to be here while I'm having a momentary failure of resolve. I'd take advantage of that if I were you."

"What do we do now, then?"

"Now, I wait until I think enough time's passed for my wife to have gone to her mother's. I need to get something from home and the best case scenario otherwise is me getting yelled at for three hours and I really can't be bothered with that right now."

"You don't seem very upset," noted Collins, studying him with affected disinterest.

"Odd, isn't it?" agreed the Doctor. He wasn't sure what to make of that himself. "Perhaps I'm repressing something." He checked his watch. "She should be almost there by now. If I don't come back you can assume I miscalculated. Don't touch anything."

"Wouldn't dream of it."

--

When he got home there was note from Rose on the kitchen table informing him that she'd gone to her mother's for the night and that he wasn't to try calling her. He tried anyway and got her voicemail.

He hung up and headed to the bedroom. He'd made the effort, at least. People either left or they didn't, and there wasn't much he could do about it either way. She'd calm down by the morning and then he could deal with the situation with his own puzzle dealt with and her in a better mood. Besides, if she hadn't left him by now she wasn't going to.

He collected the sonic screwdriver from a shoebox on top of the wardrobe and slipped it into his pocket. He could think of a few things in the TARDIS that might be handy, but that would just take longer and he was itching to get back to the park.

He caught a glimpse of himself in the mirror and stopped. He didn't look like someone who worked in a Tesco Metro. He looked alert and determined and not entirely tied to the Earth. Like someone who had taken down governments and started revolutions, someone who had seen things no one else had, someone who existed completely in the moment and knew that he had total control over what happened next.

The Doctor looked in the mirror and wondered where Steven Foreman had gone.

He anchored himself with Rose and Winifred and the set of his muscles altered subtly, giving themselves up to the gravity of the Earth.

"You," he told his reflection, "are an idiot."

--

They stood in Jackie's kitchen, sharing the room with an uncomfortable silence. Jackie had taken Winifred out to get ice-cream in a gesture the Doctor suspected of having been Rose's idea. It didn't really seem like a good sign.

Rose put the kettle on and got a mug out from under the sink.

The Doctor tried to think of something to say. "I'm sorry," he said.

"No, you're not." Rose threw a teabag into her mug. "Are you going back to the park?"

"Yeah."

"So you've just come here to make yourself feel better."

This, he had to admit, was probably at least partly true. "No, I was worried about you. I should have told you what was going on. And I shouldn't have taken Winifred with me."

Rose stared at him. "I'm sure lots of people would take their four-year-old daughter to see an alien spaceship. I can see why you wouldn't think there was anything wrong with that."

"I didn't know what it was. I just thought there might be something going on."

"She said there were dead birds. Oh, and the army. She wanted me to take her back to see everything. It's alright that I had to say no, because she doesn't like me anyway."

"She loves you."

"Doesn't mean she likes me. I'm not clever enough for her. I don't tell her stories about monsters and aliens."

"You could if you wanted to."

Rose threw the mug at him. He ducked and it smashed against the wall behind him. "You said she'd be normal! I wanted one bloody thing that wasn't weird and what did you give me? What is she?"

His mouth went dry. "She's our daughter," he said.

The kettle boiled, unnoticed. "Don't tell me you haven't wondered," said Rose.

"She's a bright and well-behaved little girl and most people would be happy about that."

"But what Iis/I she?"

"She's human."

"Her mother's human. That's not the same thing." Rose realised what she'd said and stopped. "I'm sorry. I didn't mean... You know I didn't mean it like that."

He felt something icy curl itself around his gut. "Yes, you did," he said, in tone of perfect calm. "Otherwise you wouldn't have said it."

"People just say things. It doesn't mean the things they say are true. You're human. I know that. She's human and you're human and both of you belong here."

Something hit him. "I've got to get back to the park."

"Give me the key first." She held out her hand.

He stared at her. "Rose... I know you're angry, and you've got every right to be. That thing's let something out that I didn't think was in me anymore. It's like it flipped a switch and I can't keep hold anymore. But I'm going to fix it and I'll be alright again. You can't just throw me out because-"

"Not that key."

"Oh." He took the TARDIS key from round his neck and handed it to her. "Yeah. Probably a good idea if you hold onto that for now."

"I just want to make sure you come back."

"I will," he said, and was fairly sure that he meant it.

--

"Blow it up."

Collins looked at him as if he were mad. "What? I thought you wanted to look inside it."

"I did. That's because it wants me to. It's not just birds that thing messes with. It's a spy, Mr Collins. It's been under there for years listening and cataloguing and now it's been called back."

"So? It crashed. It's not going anyway."

"But it's not dead. And it won't stop trying to leave. It'll start drawing things to it hoping they'll fix it. Not all of those things will be nice. Besides, it's giving me a headache. I don't take kindly to having my DNA unravelled by a machine."

The Doctor realised he shouldn't have said that when he saw the man's expression. "I think it recognised me. I'm a bit of a celebrity in some parts. I have lovely double helix, but does have visible seams where the base pairs meet. That thing tried to revert some of the alterations. It was trying to make itself a little friend."

"Your little girl was quite keen on having a look inside it."

The Doctor shrugged. "So were you. Human's not a synonym for stupid, you know. Other than colloquially." He looked down at the alien machine and tried not to want it. "I really would blow that thing up if I were you. Quite soon. You can say it was a doodlebug of unusual size. And shape. And origin."

"Can't we just switch it off?"

"Oh, go on. The military love destroying beautiful things. It's what they're there for."

"But-"

"Mr Collins, I'm currently trying to ignore a side of myself that's been known to blow up planets. It's getting quite difficult. I know you lot want the alien, but I don't and I might get a bit angry if you don't just take my advice and get rid of that thing. Now. And so I'm going to stay here until you do that." He rubbed a hand over his eyes. "And then I'm going to go home and sleep until my genes shrink to fit."

--

He'd given her another name, one that no one else knew. It was constructed from parts that didn't belong with each other, and it was sentimental and stupid of him and she probably wouldn't be able to pronounce it anyway.

That was what he'd passed on: a dead name and altered alleles.

"She's got your eyes," said Rose, watching Winifred string daisies together.

"Eyes are quite useful," he agreed. "I think on balance it's better to have them than not."

It was a lovely day. They'd had to take the bus to get to a park that hadn't just been the victim of a controlled explosion, but the Doctor felt that this was quite acceptable for a family day out. The grass was warm underneath him and the sun was doing its thing with unusual abandon.

"I told Tesco I had leprosy," he said.

Rose laughed. "Liar."

"How do you know I didn't?" He leaned over and kissed her. "Do you think your mum would take Winifred for the night?"

"Hormones kicking in again, are they?"

"I just think we should spend some time together without having to worry about our little parasite. Me and you and no one else. And yes, they are."

Winifred came back with feather stuck in her hair and trailing daisies.

"Your grandmother wants you to visit her tonight," he told the girl. "She wants to talk to you about your uncanny ability to interrupt a romantic moment."

"Will she let me stay up late?"

"That depends how easily I can bribe her with Tesco vouchers. Here," he said, "I've got something for you. I was going to give it to you on your birthday, but you might as well have it now."

"Is it a puppy?"

"Sadly, no." He took the key from round his neck and put it on Winifred. Rose gave him a look he couldn't quite decipher.

"It's just an old key," he said. "I don't need it anymore."