AN: I'm changing that Oswin is still a hologram and adding in that she made herself an android body at some point in the intervening fifty years between the end of 5TC and this.

Who's Afraid of Rose Tyler?

4

Thursday

It was gone noon. Rose hadn't gone to bed late but had slept in severely once again. She still felt like she was recovering, both physically and mentally, from her jungle excursion. And she still hadn't had any contact with her husband or Donna.

She got up not long after waking, hours after everybody else had gone to school, and began rummaging around in the kitchen for something to eat. She landed on a tub of olives, a day past the best before but still looking and smelling good enough to eat. She didn't know why they had olives in since she'd never seen either the Doctor or Clara eat one, but waste not want not. They tasted just fine.

She was picking out olives with her fingers and trying to decide what to watch on television, still in her pyjamas and having just barely brushed her teeth, when the doorbell rang. Maybe Clara had a parcel coming and had forgotten to warn her. She went up to the front window and peered out, but it wasn't the postman, it was Benji. He spotted her and waved a little. Olives still in hand, she went and opened the front door.

"Fancy seeing you here," she greeted him, "Did you have to look up Clara's address, or do you already know it by heart?"

"Very good, it was on your release forms. Can I come in? I have something for you."

"Please," she stood aside, shutting the door behind him.

"What's this, then? Olives for breakfast?" he asked, finding his way into the living room.

"They haven't done a big shop in a while, there's not much in," she shrugged.

"No cereal?"

"Maybe I wanted olives. Nobody else is gonna eat them, they're already out-of-date," she said, popping another one into her mouth. He gave her a funny look but didn't bring it up again. "What did you want, then?"

"Just to give you what you asked for." He reached into his jacket pocket and took out a glass vial of blood. "It's not the anaesthetic isolate, it's a blood sample from the latest victim-"

"Veronica. Veronica Lowell."

"Yes. Nobody's claimed her body yet, so I was able to get you a fresh sample. I don't need it back, so I'd recommend destroying it when you're done with this 'analysis'," he told her. She took the blood, holding it up to the light for a minute. Thick and dark. "Hard to get a blood sample from a woman who's been dead for a few days."

"Why have you done this for me?"

"You asked, didn't you?"

"Well, yeah, but I thought…"

"I want to see this killer taken off the streets as much as anyone," he said, "And if that means I've got to get the collaboration of the Doctor and her… what are you to her?"

"Ex-girlfriend," said Rose.

"If I need the help of the Doctor's ex-girlfriend, then that's what I'll… hold on, you're her ex and you're staying here with her and her new wife?"

"Clara's nobody's 'new' anything, they've been married for fifty years. I knew the Doctor three hundred and fifty years ago now. Although, Clara and I are the same age."

"Sounds like a riddle."

"It does, I suppose. But it's not that awkward. I was with the Doctor when she was still a man, I'm not into women particularly."

"…What do you mean, 'still a man'?"

"Oh, haven't they got to regenerations with you yet? What do you know?" Rose asked.

"I know she's an alien and Clara's a manifest."

"Yeah, well, that's… hold on, I'll see if I can find…" Clara had so many photographs. Not only were they covering the walls, arrangements and displays from various times in various sizes, but there were a few on the fridge, too, stuck with magnets. Including one in particular that Rose now went to retrieve.

It was ageing a little but had scribbled on the back in Clara's handwriting: 11 & Mattie, 2023. There he was, the Eleventh Doctor, with Matilda as a child suspended over his head. At first glance, it looked as if it had been snapped with him throwing her in the air, but Rose had been there that day, too. Clara had been levitating her with telekinesis because she'd gotten into superheroes that year. For a whole day, Mattie could fly. They'd put that on the fridge after she had moved in.

"Here he is," said Rose, showing the picture to Benji, "That's the Doctor, the Eleventh Doctor; he looked like that when Clara married him. You've only met the Twelfth. I'm married to the Tenth."

"Right… so, when you said your husband is the Doctor's brother-"

"It's a bit easier to say 'brother' than 'past life'. When she dies, she regenerates, heals and grows a whole new body," Rose explained. "It's not that unusual, there are jellyfish that do it here on Earth. It's funny, you lot – humans – would think of them as so… inconsequential. When I look at them, they burn like the sun."

"You're not a human?" he asked, looking between her and the photograph.

"I don't know. Maybe. I'd like to be." She sighed. "It's hard hanging on to it all."

"…Is that Matilda? In the picture?"

"Yeah," Rose smiled, remembering that day. Martha was there, just out of frame, with Clara. Mickey had taken the picture with Clara's camera. It felt like a lifetime ago. "Anyway. That's all a story for another day. I've got to get this sample to Oswin to look at."

"Rose…" he began, slowly, "What are you? Really? You can't only be a manifest."

"Being a manifest just opened something up, something else. But I don't know how to describe it. I'll see what Oswin says, and get back to you, how about that?"

"Yeah… if you get anything out of that sample, you'll tell me, won't you? Clara's got my number."

"I'll keep you posted."

"I'd better be away. I've got an appointment, I don't want to be late."

"Never a dull moment for a copper." She followed him to the front door. "Don't tell the Doctor I told you that stuff about her, by the way. She thinks you're a twat. No offence."

"None taken." He stepped outside. "Let me know what you find out."

"I will, I will. I'll see you later." He waved again and she shut the door. Now was the real dilemma: did she finish eating her olives before or after she went to see Oswin on the TARDIS?

She settled for after, putting them back in the fridge – returning the photo as she did – and making up her mind not to linger for too long in space. She made herself decent, washing her face, borrowing some of Clara's dry shampoo, and throwing on whatever clean clothes she could, and headed off. She'd change the bandages on her feet again later, when she got back.

Even for Rose Tyler, it wasn't easy to teleport straight to the TARDIS. That was largely due to the fact there were three of them in circulation, all indistinct duplicates. One belonged to River Song now, following the Ninth Doctor's death or disappearance in strange circumstances some thirty-five years ago. The second belonged to the Tenth Doctor. And the third, of course, was helmed by Jenny. She desperately didn't want to end up on the first two, and as all three TARDISes existed simultaneously across spacetime, that was easier said than done.

But she pinpointed it eventually. Around her materialised Jenny's luminous interior, bright and celestial with white walls and shades of pastel pink and blue lighting. The central column glowed like light through a prism. It could only be Jenny's; the Doctors' had been a lot moodier since the Time War, and even though Jenny herself was a brooding presence as well, it didn't show through in her design.

There were only three doors in there. One leading to the exterior, one leading deeper into the ship, and the third at the bottom of a gentle ramp leading directly into Oswin's laboratory. Despite redesign after redesign, Oswin's lab had remained static, exactly where it had been when Eleven had first let her build it.

She headed straight there, hoping Oswin was in and not in too good of a mood. Oswin in a good mood was almost as unbearable as Oswin in a bad mood.

Luckily, Oswin was in there, and she wasn't alone. There was Adam Mitchell, too, building a Lego set while Oswin leant over a desk covered in electronics and mechanical knickknacks. She was wearing an old, dark red hoodie of Adam's, hood pulled up, and a monocle, hunched over the desk in her floating wheelchair. Rose knocked on the nearest wall.

"You don't have to knock, I can hear the…" She glanced up, stopped talking. "Oh. I thought you were Jenny."

"Sorry to disappoint," said Rose.

"I'd be more disappointed if she was back here, she's been badgering me all day. Coming and going non-stop. I keep telling her, Jenny, I just don't want to watch you come."

"Uh… hello, anyway, to both of you," said Rose, approaching, hands in her jacket pockets.

"Aren't we beyond hellos, after all this time?" asked Oswin, looking at her with one giant eye, magnified by the monocle.

"Well, I thought it'd be polite."

"You? Polite? What for?" asked Oswin.

"It's just nice, isn't it?"

Oswin removed the monocle and studied Rose very pointedly. Rose shifted uncomfortably.

Then Oswin asked, "Are you trying to fuck me?"

"What? No, of course not, I'm-"

"Oi," Oswin turned to get Adam's attention. He looked up from his bricks. "She's trying to fuck me."

"Why would she want to do that?" he said, then smiled warmly at Rose, "Hello. How's things? How're you keeping?"

"Not too bad," she said. "Although, now that I think about it…" She cleared her throat. "Are you building Lego?"

"Yeah," he said, then went on the defensive seeing how she was looking at him, "It's a very complex set, for adults – you see the box, it says sixteen plus."

"And how old are you, again?" He scowled and went back to the instructions.

"Why are you darkening our doorstep?" said Oswin, "Has Clara got sick of you? Kicked you out?"

"No, she hasn't kicked me out."

"Clara wouldn't kick Rose out," said Adam, "She fancies her too much."

"That's true," said Oswin, "You should see the things she thinks about you. Filthy."

"Yeah, well, she invited me to run away into the woods with her and masturbate the other night, so maybe she's not that good at keeping things to herself. But – enough about that," she shook her head, then pulled out a chair next to Oswin, who looked at her suspiciously. "I need a favour."

"The big, bad wolf needs a favour from a humble Dalek, who could've guessed," said Oswin, dry. Rose took out the vial of blood and held it up to her.

"There's a serial killer out in Brighton, killed four people so far. Police pulled me in for it because I found one of the bodies the other night. They say that they've all been injected with some sort of anaesthetic and had their organs removed and blood drained, then they get dumped naked in a cemetery."

"Have you talked to the-"

"The vampires? Yes. Did that first. If you could just take a look, please. I'm trying to catch him."

"But I've already looked at it," said Oswin, confused.

"Have you?" Rose frowned.

"Yes, it's right there," Oswin nodded at the vial, "I'm looking at it right now. I'm only about sixty per cent sure it's human blood, from this distance." Rose stared at her. "What? You asked me to look at it, I've looked at it."

"Oh, for-"

"I'm kidding! I'm kidding. Yes, I'll analyse it for you and see if I can solve your crime."

"Don't talk about it like that. Four people are dead."

Oswin stopped, then went on, softer. "I'll analyse it. The chemistry equipment is over there." She took the blood vial and spun around in her wheelchair, rocking a little from side to side.

"Will that thing fall over?" asked Rose.

"No, no, it's got a gyroscope in it; stabilises the quantum levitator very nicely," said Oswin. Rose followed her over to the chemistry set, dragging the chair behind her and setting it down again at her side. Oswin ignored all the flasks and burners and pieces of tubing and went straight for an enormous instrument, two feet high, mounted on tiny wheels on the desk.

"What's that?" asked Rose.

"Electron microscope," said Oswin, "Proprietary, but clunky – I haven't had the chance to draw up any blueprints for a smaller form factor. You know, that robot dog of the Doctor's is probably just as capable of analysing blood, you didn't need to trek all the way to the Butterfly Nebula."

"Is that where we are?"

"Roughly."

"Can't your monocle analyse it?"

"No, it's just a monocle."

"…Why were you wearing it?" asked Rose, watching Oswin tap out a tiny drop of blood onto a slide and then put it into the microscope.

"To magnify things, obviously."

"Yeah, but, you don't have any eyes, do you?"

"Pardon?"

"You're just an image. You see out of the thing that floats around, the Sphere, don't you?" Oswin gawked at her. Adam put his Lego down and looked over at her in shock. "…What? What've I said now?"

"I haven't been a hologram for decades."

"Haven't you?"

"No!"

"Oh. Then, what are you? If you don't mind my asking."

"If I don't mind-!? I mind you paying so little attention to us for half a century that you don't know I built myself a body. Can you believe this?" she asked Adam.

"It is a bit out of order," he said.

"Ooh, alright, bloke with a door in his head's calling me out of order. Or are you gonna tell me you've had that fixed?"

"…Irreversible procedure…" he mumbled.

"To be fair," Rose began, "Why would I really know what you two have been doing? He's been too busy to talk to anybody for fifty years, and you… you're a twat."

"I thought you were being polite?" said Oswin. Rose stopped talking and leant back in her chair.

"Sorry," she said after a moment.

"You're a bit bloody defensive, aren't you?" said Oswin, "Then again, I suppose you always have been. The Doctor gets married to Clara, and there's you – defensive."

"Long time ago, now. And Martha never liked all that – being caught in the middle."

"Funny," said Oswin, "I'm sure plenty of people dream of being caught in the middle of you and Clara. Mitchell does, I bet."

"Too many legs for me," said Adam. Oswin laughed.

"…So, wait," said Rose, "Can I ask you something?"

"Yes," Oswin nodded, "You can kiss me."

"'Scuse me?"

"To check that I've got a solid body, like I said, and I'm not a hologram. It's the easiest way to test, because of the tongues."

"I wasn't gonna ask that."

"You were just going to do it? That's fine. Much sexier, really – assertive."

"Yeah, no, I'm not kissing you."

"Then why did you ask to?"

"I didn't!"

"Are you sure?" she looked up from the microscope. Rose was glaring at her. "What?"

"I wanted to ask about your legs."

"I see. You want to know, why, if I built myself a new body, am I still hobbling around the place?"

"Well, yeah."

"I rather fancy myself a Byronic hero, and if both my legs were working, it would ruin the image, wouldn't it?"

"Right… what's the real reason, though?"

Oswin sighed, "I lost my leg a long time ago, and it's been a part of me ever since. I'm not erasing something about myself no matter how… inconvenient it might be to you backwards, twenty-first-century goons with your lack of hover technology and allergy to ramps."

"But it's painful, isn't it? The leg that's still there?"

"It was painful when I was alive, it's painful now. I'm living with that. Or dying with it, if you'd prefer."

"And the two of you, you can-?" Rose began, pointing between them. "Because before, when you were a hologram, I thought you couldn't... except in your VR-whatsit."

"It was a simulation," said Oswin, "Yes, we can have sex. I just told you, the tongue is the best test." Rose didn't ask her any more questions about that, for fear that she'd be propositioned.

"…Oswin," she began, serious. "If I ask you something, will you tell me the truth? And not speak in riddles, like the Doctor?"

"I'll do my best."

"Do you think I'm human?"

"No. But that doesn't mean you're not alive, and that's what you're really asking me, isn't it?" How did she know that?

"I don't know if I am, sometimes. Everything's always… far away. Hard talking to people when they're barely gonna be around for eighty years and you can see their whole life laid out in front of you."

"You're your own thing, Rose. Not many people can occupy a quantum superposition without going mad – and believe me, going mad is easier than you think."

"You know," said Adam, "There are other manifests with powers like yours. Not quite like yours, but there are others who can time travel."

"But they're just moving around," said Rose, "They can't see it."

"No, what I mean is, there are support groups, and things, for manifests, where they can go talk about stuff like this," he explained. "It's still a bit underground. A few years ago, I met someone who was immortal, and they don't have a big network of other, immortal people to spend time with, like we do."

"That's because they were a wanker, though," said Oswin.

"Well… he was, a bit," Adam admitted, "Didn't like women much."

"Brilliant…" said Rose, unconvinced. Oswin went back to her microscope, Adam to his Lego. "Is Jenny around, do you know?"

"Oh," said Oswin, "She's got this alligator. Horrible."

"An alligator? Where?"

"Down in her new meat locker, off the kitchen."

"She's keeping an alligator in a meat locker?"

"It's dead," said Oswin, "Wasn't that clear? Anyway, it stinks, she's been down there with it for ages. Clara's still asleep."

"I might go find her. She used to be in the police, didn't she? Maybe she'll be able to help," said Rose.

"Sure, I'll be able to do this a lot quicker without you breathing down my neck."

"Charming, as always," Rose stood up. Oswin smiled at her.

"Don't say I didn't warn you about the smell."

"I'm sure I'll cope."

But in truth, the smell when she got near to the large, iron door in the kitchen was overpowering. Salt and meat, very potent. She approached carefully, listening to the rhythmic hacking of a meat cleaver coming from within, and then knocked on the door. The hacking stopped and shortly, Jenny hauled open the door, wearing a plastic apron covered in blood and a pair of clear, safety goggles.

"Hello?" she said, surprised, "I thought you were Oswin."

"And she thought I was you earlier," said Rose.

"Did she send you here with a message? If this is about the lucky cats again, I've told her a million times, I didn't know they were radioactive and it's not my fault what happened to those prawns."

"I… what?" said Rose, "She didn't send me with any message about cats or prawns or – what were you doing to the prawns?"

"It wasn't my fault!" said Jenny.

"It's nothing to do with that, I wanted to ask you about something – some murders. Not prawn-related at all, as far as I know."

"Well, is it urgent? I'm in the middle of something."

"Yeah, they told me about the alligator. I can talk while you, uh, keep cutting that thing up," Rose nodded at it, behind Jenny, a half-dissected gator on a metal table.

"Do you want some nose plugs, or anything? They'll make your ears pop."

"No, I'm fine. It's not the worst smell in the world."

"It's fresh!" said Jenny, letting Rose into the meat locker and then shutting the heavy door behind her. It was ice cold and lit by one solitary, fluorescent bulb overhead. Rose could see her breath in the air. The alligator was bright pink, its skin already hanging from a hook nearby, claws attached. But its head was still green and scaly.

"Where do you get alligators from? Did you buy it?"

"No, hunted it."

"From the wild?"

"Their population levels are carefully monitored," said Jenny, putting the cleaver down and picking up a slender filleting knife instead. "If you're eating real meat, an animal always has to die somewhere in the chain. You eat meat, you just don't like seeing it."

"Maybe," said Rose, watching her begin to carve a thick chunk of pink flesh from the alligator's back.

"And I'll use the whole thing, besides. That skin makes a strong leather."

"Can't you clone it, though? Isn't meat all grown in labs these days?" asked Rose.

"What do you mean, 'these days'? You mean the 2060s?"

"Yeah."

"Then, sure, plenty of meat is artificially cultured in Agristats around that time."

"In what?"

"Agricultural Stations," said Jenny, dropping a big slab of fresh meat into a sink full of cold water behind her. There were a few more fillets gurgling away there already. "It takes a lot of energy to produce lab-grown meat. They use solar panels on purpose-built space stations in low-Earth orbit. Wait until they build the Helios Array in the 2120s; space farming clusters all orbiting the sun, massive energy, creating enough food for the entire solar system."

"Why do you know so much about it?"

"It's food," Jenny shrugged, "I'm a chef – sometimes. Well, most times. I grew up in the bayous outside New Orleans, for years I survived on alligators. The things I can do with one of these – you'll find out if you keep hanging around Brighton. I'm going to take the Doctor some of these cuts."

"Can't wait…" said Rose, unconvinced by the alligator. But she'd still try it. It couldn't be worse than the beef-flavoured slushie she'd had with Adam on Satellite Five.

"What do you want, anyway?"

"Not to talk about lizards, honestly. I-"

"They're not lizards," said Jenny.

"Sorry?"

"Alligators, they're not lizards, they're crocodilians. It's different. You should learn a thing or two about reptiles, it might come in useful one day."

"That's… ominous," said Rose, "But, I'm investigating some murders, a serial killer, in Brighton." She explained, yet again, the circumstances of the four murders so far; the MO, the cemetery, her arrest, what the vampires had said, and how she had Oswin working on a blood sample as they spoke. Jenny multitasked, both butchering her reptile and listening to Rose carefully.

"What about organ harvesting?" said Jenny right away, when Rose finished.

"Police think it's too weird for organ harvesters to keep dumping the bodies in the same place, especially with them staking the entire graveyard out," said Rose.

"Hm… maybe. Could be invisible."

"You mean, like, alien organ harvesters? What would they want with human organs? Wouldn't they need organs from their own species?"

"You can eat the liver from an alligator, you know. Cow hearts, pig brains, lamb kidneys, deer tongues. All edible."

"You think… you think someone's eating them?"

"Nah, probably not. Like you say, dumping them in the cemetery is too odd. Any interstellar organ smuggling ring I've dealt with has always ejected the waste matter into the nearest star. Plus, it's a bit wasteful to only take the organs, leaving all the proper meat on the bones."

"I feel a bit sick…" said Rose. "You're talking about eating humans."

"My wife needs to drink human blood to stay alive, you know," Jenny reminded her.

"Still…"

"The other thing, most organ harvesters wouldn't pick people off from Earth. They go to frontier colonies, which don't exist yet in the 2060s. When you think about it, an isolated colony is a bit like a farm where the livestock looks after itself."

"That's horrific. How many gangs of marauding human-eaters have you met, to know so much about it?"

"Ran into a squad of them when I was captaining this pirate ship. Gave them over to the Shadow Proclamation, in the end. Humans are a Level Five species, it's against Galactic Law to go around eating them. I've heard Vastra talk about eating people, before, and Silurians breeding early hominids for a food source."

"I really don't want to deal with anybody trying to eat humans."

"Well, like I said, they wouldn't leave so much potential food behind by only taking the organs."

"You're dark, you know," said Rose, "You've seen all these awful things."

"That's life, seeing awful thing after awful thing. Humans are just better at forgetting it."

"…I did see a human farm once, kind of," said Rose, "I was maybe taking a backseat at the time-" She'd been possessed. "-but there were these people, these cat nuns had them, locked up in a farm and infected with diseases to try and create cures. It was a hospital."

"If anything, that's worse. At least the meat humans are supposed to be kept healthy."

"Until they're killed to be eaten."

"Well, we all have to die one day." In talking to Jenny, Rose was suddenly feeling a lot nearer to humanity than she had before. "Only the richest weirdos pay for fresh, organic human meat. It's just as easy to culture a human steak in a lab as beef." She cut another big piece out of the alligator, then moved onto its head. "Some of the best bits are in the jaw here."

"Great… Clara's asleep, then? Oswin said."

"She usually is at this time."

"Isn't there anybody else here? Nios? Where's she?"

"She's not here often, she's Dr Cohen's full-time carer now, really," Jenny explained.

"Carer for what? She can't be that old, what's wrong with her?"

"She's eighty, and it's cancer – breast cancer. Aggressive."

"Oh, right."

"Can't you see that? In the time vortex?"

"I try not to. And the time vortex is more… emotive. It's feelings, at its heart. Plus, what am I gonna do? Find out when people are dying and then go hover over them, like an angel of death? There's no afterlife to welcome them to."

"Yeah, well, careful talking about afterlives around Nios, if it comes up," said Jenny, "It's a very sensitive subject around here."

"What do you mean? Why?"

Jenny sighed, but then told her, "Cohen wants to be a hologram. Oswin has everything in place, but Nios isn't happy about it."

"Nios is against holograms? Isn't it just another type of AI? She's an AI."

"You're asking the wrong person, I'm not involved. Oswin won't talk about it anymore, either. She says, she'll honour Cohen's last wishes, whatever they are when it finally…" She paused. "We'll see."

Rose's phone buzzed. A text from Oswin, one word: Lab.

"I'd better go, she's done with this blood."

"I'll come with you, I want to know what she's found," said Jenny, peeling off her rubber gloves, plastic apron, and safety goggles. She washed her hands quickly and then followed Rose out, who was glad to be away from the dead alligator.

"So, you're going to…" Oswin began when the doors to the lab slid open. But then she noticed Jenny behind Rose. "What's she doing back here? Getting her stench on everything – haven't I told you already today?"

"It's fresh meat, it's not a bad smell," Jenny argued.

"You'll stink up my entire laboratory – tell her, Mitchell," said Oswin.

"I'm not getting involved," he said, eyes on his Lego instructions.

"I just wanted to know what's going on, Rose has been telling me about the murders," said Jenny. "If you really want me to leave, though-"

"Fine. Just stand over there, keep quiet, and look sexy. That's all you're good for." Jenny rolled her eyes.

"Are you two done?" said Rose, looking between them. Neither spoke. "Right, put me out of my misery, what did you find out?"

Oswin clapped her hands, "You're going to like this. Probably. Actually, I don't know, maybe you'll hate it. But I've managed to isolate your anaesthetic and it's a fascinating compound – a naturally occurring molecule found on Earth, of all places! You find it in a plant – well, a root, really – nicknamed 'sleepwort', as best I can translate."

"If it's naturally occurring on Earth, why hasn't anybody else been able to identify it?"

Oswin got very excited at that, "I'm so glad you asked! Sleepwort has been extinct, for sixty-five million years. But this compound here used on your latest victim-"

"Veronica," said Rose.

"Yes. Veronica has been packed full of prehistoric anaesthetic that was, remarkably, distilled in the last week or two. You see, the plant cells start to melt away as soon as it gets reformulated from the root. They degrade and all the cytoplasm leaks out, making this stuff unstable and useless if you don't use it right away. It still takes a few weeks, though, and this is only just starting to break down."

"Brilliant. Sixty-five million years, that makes the killer – what? A dinosaur?" said Rose dryly.

"Yes! Precisely," Oswin beamed at her. Rose didn't quite get it. "Sleepwort is, according to the TARDIS archives, used primarily for medicinal purposes by everyone's favourite species of reptilian humanoid. Your killer is a Silurian. Or somebody who knows a lot about them, their medicine, and where they keep their ancient plant samples in stasis. But for my money, it'll be the former."

"Silurian, you see," said Jenny, "Human farms."

"I doubt you'd bother anaesthetising them with such a complicated formula if you were eating them," said Oswin, "What happened to a good, old-fashioned bolt gun? I bet you didn't give that crocodile of yours any anaesthetic before you shot it in the head."

"It's an alligator, which you know," said Jenny.

"Stop talking, both of you," said Rose, "How would a Silurian be able to hide from the police like that? Brighton plod might not be the best in the world, but they'd notice a lizard person going around killing people."

"No idea," said Oswin, "Invisibility? Basic camouflage like that is actually very simple, I'm sure the Silurians would have developed it before they all went to sleep. But cloaking can't hide everything, and I might have just the thing if you're tracking down a rogue reptile. Unless somebody has been moving my stuff again," said Oswin pointedly, picking up bits and pieces from her desk as she searched.

"I haven't moved anything," said Jenny, apparently the one Oswin was talking to.

"Really? You haven't nicked something? Again?"

"No."

"You won't know this, Rose, but Jenny's taken to stealing things out of my lab."

"It was one tokamak, one time, and I saved thousands of lies with it."

"Yes, but you didn't have the decency to text and ask, did you?"

"How many times!" Jenny threw up her arms, "I can't text you when I'm in a pocket dimension! The phones don't work properly!"

"You didn't even leave a note! Just like you didn't tell me everything that was going on with these prawns-"

"Not the prawns, again! I've apologised countless times for that!"

"It's not about the-"

"You two have a real psychosexual thing going on here, don't you?" said Rose loudly, interrupting them.

"Yes," said Oswin, picking up a stack of paper, "I'm psycho, she's sexual. What did you do with my thermal contact lenses, you little gremlin?"

"What do you need thermal contact lenses for?" asked Rose.

"Finding snakes," said Oswin, indifferent. But Jenny reacted strongly, going red.

"I can't believe you'd just say that," she was furious. Oswin ignored her completely.

"What's going on?" said Rose, "What snakes? Where?"

"It's better you don't ask about the snake, in my experience," said Adam quietly.

"Tell me, what're you up to?" she asked Jenny.

"…I'll tell you," said Jenny after a moment, "But you have to promise not to tell the Doctor."

"Alright, fine."

"We adopted a snake, a while ago."

"Is that it?"

"It's quite a large snake."

"It's a Titanoboa!" said Oswin, gleeful, "Biggest snake that ever lived!"

"And it's here? On the TARDIS?"

"I rescued him!" Jenny protested, "There were these pet smugglers, time travelling, fetching dinosaurs for people and all sorts. They took him out of the wild and raised him in captivity, he wouldn't survive in the wild now."

"What do you feed it?" asked Rose, dreading to think.

"Big fish," she said, "Only twice a year. The bigger the snake, the less often it needs to eat. But I don't want the Doctor finding out and getting involved, telling me what animals I can and can't keep on here."

"She's making a big fuss over nothing," said Oswin, "But I'm serious, what have you done with the contact lenses?"

"…I don't remember," said Jenny.

"If you've lost them-"

"They'll turn up! Clara probably knows where they are, I'll ask her."

"Oh, great, that's great…" Oswin grumbled. "Bloody hell. Fine. Do you like glasses, Rose? I've got thermal glasses, too – a lot harder for Jenny to lose. Useless." Jenny scoffed. "If you help me look, it'll be a lot easier. There're glasses all over this place, just show them to me when you find them."

She wasn't lying, they were all over the place, and all designed to carry out increasingly minor things. Oswin had come a long way since making Adam Mitchell the glasses to correct his colour blindness. Rose picked them up one after the other, Oswin shaking her head each time.

"You and Clara both like glasses, don't you?" said Rose, picking up and examining her fourth pair.

"Clara and I are very similar, if you hadn't noticed," said Oswin, "Some people say she looks just like me."

"Yeah, yeah. How about these?"

Oswin clicked her fingers, "Yes. Those are the ones, they do the thermals." Rose put them on. Grimy. "There's a tiny button on one of the arms, just – there you are." Rose was startled when she switched it on. There were the three of them: Jenny glowing brilliant yellow, robotic Oswin a dull shade of pale green, and Adam Mitchell an eerie, dark blue, thanks to his cryokinesis. "You'll be able to spot a reptile in disguise with no trouble at all wearing those, with the cold blood."

"I still don't know where to look, though," Rose took them off, "Wander around Brighton? Hang about that graveyard and hope I get lucky?"

"Well, even if your Silurian can turn invisible, I doubt he's carrying the bodies very far," said Jenny, "I wouldn't want to carry a dead body too far. If nothing else, it means you're more likely to get caught, the more time you spend with it."

"And he always dumps them in the cemetery, the same one, so probably around there somewhere…" Rose thought, "But it was still surrounded by police the other night, and me, and nobody saw anything."

"What about the tunnels?" asked Oswin, "Have the police looked into those?"

"Tunnels?" said Rose, "What tunnels?"

"The one those trees made in September when they invaded. Their roots left all these tunnels behind, and I don't think they've all been filled in yet."

"Of course!" said Rose, "If they dug through the graveyard, he could be dragging the bodies through there that way…"

"And I think," said Jenny, "If he leaves them all in the same place, he probably gets them all from the same place, too. And that won't be too far away, either. Especially not if he drugs them so they're unconscious."

"Homeless shelters or soup kitchens near that cemetery, then. I just go to one of those, and see who turns up," she decided, "Scan them with this state-of-the-art lizard detector."

"Great idea, very good," said Oswin.

"It was your idea, both of you."

"Don't give them too much credit," said Adam.

"I barely did a thing," said Oswin, "I'm only the fluffer. But feel free to call in on us whenever you like – sometimes it gets tiring having Jenny be the only blonde in the room."

"Oi," said Jenny.

"Go keep cutting up that crocodile, pervert," said Oswin.

"I'll be heading off to Brighton, then," said Rose, "Clara'll be able to help me with this homeless shelter stuff. And I'm sick of you. Not Adam, just you two." Adam smiled at her.

"I did tell her explicitly not to come back here today," said Oswin. After another bit of mind-numbing bickering from them, Jenny got annoyed enough that she stormed out of the lab, retreating to her meat locker.

"Thanks for your help, anyway," said Rose.

"Tell me if you catch him and find out what he's doing with the organs," said Oswin, "I'd love to know."

"Yeah," said Rose, "Will do." She dematerialised from the TARDIS in a cloud of atomic gold dust.