Chapter One – A swarm of wasps

Why did they always have to come to Earth? Home of brilliant people, sometimes brilliantly stupid but nonetheless courageous, curious, inventive... His second home. Only home, really, apart from the TARDIS and the space-time vortex. And for some reason it was constantly being invaded by aliens who had all the universe to choose from but came, unerringly, to Earth.

These were some of the Doctor's more coherent thoughts as he ran for his life, a giant globe-shaped swarm of wasps behind him.

A Flock, of all things! Hadn't his people banned them to Cabillarion IV? But that, he realized, was one of those ancient boundaries that wouldn't work now.

He jumped into a convenient-looking alley to the right, and the Flock rushed past, too fast to turn (still their major weakness, he noted). By the time it had regathered, he would be a mile away.

"In here!" A hand grabbed him by the collar and pulled him, rather roughly, through a doorway. "You're safe in here!"

He spun around, the part of him that sometimes grew exasperated with humans rearing its head, and faced the dark-haired man in front of him. "No, I'm not safe in here, and neither are you! You should come with me right now," he threw a quick look around, "all of –"

Oh no.

"Blimey, you know how to say thanks," said Donna Noble.

He continued staring at her.

"What, skinny boy? Never been told not to be rude?"

He forced himself to look away, to not wonder why for all the moons of Myle she was here, and he fixed his gaze on the man in front of him. "Seriously, this is not safe, we should run that way," he said, thrusting out an arm, "before the Flock regathers."

"Calm down, son," said the dark-haired man, who had a thick Scottish accent. The Doctor realized as he looked around that he must be a tourist guide. "The wasps have haunted this town for a week, I know where to hide."

"For a week?" asked a blonde in her forties, accent distinctly American, tone distinctly annoyed. "You said you didn't know where they'd come from!"

"Well, it's true," said the man. "Nobody in this town does." He forestalled her oncoming tirade with a shrug and a smile that begged forgiveness, and the Doctor thought he rather liked this man.

"I'm Daniel," he said, holding out his hand to the Doctor.

The Doctor threw another short glance at Donna, which she rewarded with a suspicious look.

"John Smith. Nice to meet you." They shook hands and went to sit down in a corner of the small garage they seemed to have broken into, while the others resumed their conversations in low, worried tones. "So the… wasps have been here for a week?"

"Well, let's say they started behaving like that a week ago," said Daniel. He looked embarrassed. "I thought they'd gone, I hadn't seen them for a few days, else I would have told this lot to leave..." He frowned, looking at the group of seven at the other end of the room.

"And it's just wasps?" asked the Doctor in a low tone so only Daniel could hear. "No other animals have been, er, behaving strangely?"

Daniel frowned. "Not that I know of. Why do you ask?"

"Oh, just curious," said the Doctor in as light-hearted a tone as he could muster, while simultaneously calling to his mind all the facts that he remembered about Flocks and studying Donna, wondering, hoping, praying that he didn't look familiar to her.

She caught his gaze and strode over. "You look familiar," she said without preamble. "I'm Donna. What's your name?"

"John," he said, his mind racing. Oh – of course. That moment of stupid weakness when he hadn't been able to leave her house in time. Had gone back to say goodbye, on top of that. At least he hoped that was what she remembered.

"You look familiar, too," he said, pretending to search his memories. "You from London?"

"Yeah," she said, frowning. "Chiswick."

"Oh, must've been at your house then, trying to sell you a dishwasher. I did Chiswick in one week. Right after Acton. That was one hell of a month, all of West London… I think I remember your house, live with your mum and grandfather, don't you? Was rubbish at that job, though. Good thing I gave it up."

"You must've been more than rubbish, 'cause my mum never turns down a bargain," Donna commented, in that flippant, carefree tone that he remembered so well. "Mind you, she was probably distracted that day." Her expression softened somewhat, and the Doctor almost felt his right heart swelling with the thought that, at least, the relationship between Donna and her mother seemed to have improved.

"So. These flock things, what are they?"

He blinked. "What do you mean, what are they?"

"Well, they can't be normal wasps." She lowered her voice. "Yeah, I know this lot believes they're some rabid Scottish form or whatnot…" She raised her eyebrows at him, almost conspiratorially, and he felt a thrill of recognition. "But frankly –"

"Shh!" Daniel held up a hand. "They've moved on."

The Doctor sniffed the air. Yes, that faint sulfuric smell was gone. "Right, let's move on!"

And there they were, running for their lives again, Donna and him in front. And Donna was obviously enjoying it. Oh dear, oh dear.

"Where are we running to?" she shouted as Daniel overtook them, panting.

"To my house, they have never come inside a house," he shouted back. "We'll be there in a – watch out!"

The Flock had whooshed out of an alley to the right, and while it had announced itself with a deafening roar earlier, this time it was silent. Which was a hundred times scarier, not because the Doctor was afraid of silence, but because he knew it meant that they were improving their control over the bodies they inhabited.

He grabbed Donna's hand instinctively, and it felt right.

"In here!" They ducked into yet another alley, and they were alone. The Flock had blocked off the main road, and the rest of the group had scattered. No sign of the Flock as they ran, not speaking, just looking over their shoulders every so often. The Doctor ran up to a door, and shielding his sonic screwdriver with his body, he unlocked it.

"We should we cover up all the holes," Donna panted as they were inside, and pointed at the keyhole.

He shook his head, marvelling at the same time at her presence of mind, one of the things he had first admired about her. "No, they can't get through on their own. They have to be a whole to be able to function."

She gave a dry laugh. "Looks like they're learning pretty fast, though. What's that silent trick they did just now, or did I suddenly go deaf?"

"No, you didn't. They are learning very fast." He sighed and dropped on a couch. They were in a small parlour; the inhabitants seemed to have gone away. They had left in a hurry, since there were still the traces of breakfast on the table and all the shutters were closed.

"So you seem to know what these things are," Donna said as she sat down on a chair opposite him. "Pretty well-read for a dishwasher salesman."

"More like well-travelled," he replied. "Which goes for lots of dishwasher salesmen, actually. We're the modern adventurers, you know? You should see what different tribes and cultures I've had to deal with in my time."

She raised an eyebrow at him in that half-annoyed, half-inquisitive way. "Whatever. But what are they?"

He was at a loss. What if even the tiniest mention of extraterrestrial life brought back a memory? Not that he doubted his efficiency at erasing memories, but he had never trusted the technique with humans, as they and even their brains had continued to surprise him over the last 900 years. He could never forgive himself if she suffered for him again.

But before he could reach a conclusion, Donna rolled her eyes, misunderstanding his hesitation.

"Oh come on, you don't have to treat me like some Daily Mail reader who thinks it's all a hoax. It's alien, right? It must be alien." She hesitated, and finally said, "I would know."

His hearts began to race but he forced himself to keep control of his face. "And why would that be?"

She looked a little embarrassed. "All right, don't think I'm mad or something, yeah? But... I think I was abducted or something. Cause I lost my memories of several months."

He gulped. "Right."

She grimaced. "Yeah. That's what most people say. 'Right'. And it's all downhill from there with 'sure, love' and 'nice meeting you but I really need to get to this meeting in Tanzania right now'."

He grinned. "No, I believe you. You're right. There are aliens everywhere these days."

She leant forward, suddenly excited. "There are, aren't there! And I reckon I must have been in the wrong place at the wrong time or something and seen something they really didn't want me to see."

He nodded solemnly, all the while trying to ignore the twinge in his hearts.

"So, Flock, did you call them?" She looked as excited as she ever had when there was a new world to explore, and it was such a wonderful feeling that he forgot that he was dangerous to her.

He leant forward as well. "Yeah. They're creatures made out of thought, we-ell, it's what you'd call thought but it's actually a neuromagnetic field binding them together into a community. On their home world they exist by inhabiting other species, and they're peaceful there, all lovely. Unfortunately one day they got some visitors – humans, no doubt, you just go everywhere in the name of science, bless you – who got so scared seeing them inhabit a herd of maglamites that they ran off, and that's where the Flock got the idea that it might be fun going to other worlds and scaring other species. Very unfortunately, scaring turned into hunting and hunting turned into killing."

Donna looked riveted, though at the same time slightly doubtful. "Who are you then, some alien expert?"

"Yup," the Doctor said simply.

"All right then," she said, apparently willing to believe him for the moment. "What do we do to kick them back to neuromagnetic hell?"