AN: Dark chapter here, suicide trigger warning. Some of that dark-Eleven there isn't nearly enough of making an appearance.

Amy

How To Catch A Monster

The mood had dulled to one of sinister uneasiness, everybody looking about them to spot anything out of the ordinary, anything off-colour or a smidgen of movement between the trees. But the woods around the lake climbing the sides of the mountain were dense and dark within, so it was proving difficult to see if things were amiss or not. Adam Mitchell looked the tensest of all the group though, considering he and his cryokinesis were supposedly the only things standing between them and a messy end at the claws of the Thing – unless Martha gathered herself.

"…Where did that come from?" Amy whispered. Martha was, as predicted, still out of it, and the geniuses weren't speaking. Probably thinking, then they could share their thoughts and boast about their intelligences to one another while she looked for an escape route from the soiree she'd just made up…

"I don't know," said Eleven, 'helpfully.' The Doctor then proved himself to be either an idiot, or completely confident in his own ideas, because he simply smiled to himself, and then marched off into the woods without a word. Seconds went by and nobody followed, until Amy decided that the man was quite probably the first of her assumptions, and that if nobody else was going to make sure he didn't wind up in trouble somewhere, she most definitely had to.

"Doctor, hang on!" she called, stumbling over a branch to follow him and leave the rest of the group behind.

"Come along, Pond," she heard him say, and switched directions to follow his voice, catching up with him a moment later, "Fritz and Luke are very closed-minded about this," he then told her, very quietly. She thought he looked odd without his tweed. For all the years and years (decades, probably) she'd spent travelling with him, he never seemed to be out of his daily, formal attire. He always got changed from his pyjamas before coming to drag she and Rory out.

"Really?" she asked, picking up on his disapproval of their behaviour. And she'd thought they'd all been getting along splendidly.

"Yes, they both seem to be rather ignoring the evidence that this Thing is an intelligent lifeform, whatever it is," Eleven said, holding his screwdriver out in front of himself for a reason Amy couldn't fathom, like it was a torch emitting absolutely no light (she didn't even think it was switched on). "But it piloted the bathysphere, so of course it is."

"You don't have any idea what it is?"

"Oh, I have a few, but none of them pleasant," he said darkly. Amy cared to glance back and saw they weren't being followed by the other members of the group. No doubt they all thought the Doctor had better have stayed out there with them, and then there was also the very real danger that Martha Jones might start a forest fire.

"Brainstorm," Amy tried to coax him.

"Whatever they are in that base, they're experiments. Grim ones, probably, and unethical I'd wager. There must be some reason they were all left behind when the base was abandoned," Eleven said, "I don't think they're alien. I think they're strictly of Earth-origin."

"They didn't look like anything I've ever seen before. Except… I'm sure the hands were webbed, like frogs or something, and they had massive eyes," Amy said, frowning as she tried to remember exactly what she'd seen in the base's tanks about an hour previously.

"They had gills, as well," said the Doctor quietly, "Amphibious, I think. Isn't that odd? An amphibian in a bathysphere? Could've just swum. Hmm. I'll have to ask it. I hope it can speak…" he got momentarily lost musing upon the linguistic capabilities of mutant lake-people he'd found in a desolate military base, but a noise like a twig snapping brought him back, and they both froze. Surely, another member of the group would have announced themselves? Amy couldn't help but think they'd have done better to bring something with them, like tranquilisers, or a net, perhaps.

"Was that you?" Amy breathed in Eleven's ear, but he looked at her seriously.

"No," he answered, "Was it you?"

"If it was me I wouldn't've asked if it was you!" she hissed. He nodded slightly, acknowledging this as a legitimate (and obvious) explanation.

"Suppose not," he said. She glared at him, but he ignored this, crouching a little to try and see through the trees to spot the source of the breaking twig, but he didn't have to look for very long.

The Thing lunged from the darkness, dark green and shiny with a glistening coat of watery slime and mud. It had long, webbed, but clawless fingers, and the same with the feet, except there were less than ten fingers and less than ten toes, little stumps where she assumed they'd once been. It seemed almost scaly, but moist all over like it was secreting a fluid onto its skin. Its four limbs took on a defiantly human-shape, though extra, fishlike flaps of skin hung from the elbows and the knees and the shoulders, like fins. Then there was its face, which was very dark green, gnarled and square like it had been wrought from stone with a pickaxe, and two huge, bloated, yellow eyes like – as Amy had said – a frog. Four slits cut down either side of its swollen neck, bulging at the sides and growing and shrinking as the seconds passed by and it loped towards them with a gurgling breath emanating from the wide, wet mouth rather than the gills.

Amy shrieked and Eleven jumped back from the fiend as it emerged, hanging its hands low to the ground like they were too heavy for it, though it was hardly apelike in the rest of its movements. Its pupils were dark and huge and facing horizontally in opposite directions, moving independently like a chameleon or some other lizard.

"Stay back! We're armed!" Amy shouted, leaning over the Doctor to grab hold of his hand and forcing him to unwillingly brandish the sonic screwdriver in the direction of the Thing, which was all-too human for her liking in the way it was built, like someone had taken a man, painted him green and bashed him up a bit. It cowered from the sonic when Amy made it buzz.

"Amy, no!" Eleven snatched his hand away from her, putting the sonic in his pocket and shaking his head ashamedly at her, "Sorry about her. I'm the Doctor, I'm here to help, and to listen to you," he smiled at it, like it understood facial expressions or something. Amy did nothing, she was disinclined to let it touch her. It made a noise that was half a croak, like someone with a mucus cough doing an impression of a frog.

Amy stayed still, but the Doctor stepped closer, staying crouched like the Thing was so they were on the same level, approaching with his hands open in surrender to show he meant no harm.

"Hello," he said politely, like he was addressing a child, "Who are you? Do you have a name?" The Thing said nothing, "Can you talk?" It made another gurgled-croak noise. "Ah-ha, see, Amy? He understands me. I said he was intelligent. Now, what sort of alien would know the language?"

"Isn't it the translation matrix..?" Amy asked.

"No, he knows what we're saying. I'm not going to hurt you, I'm a friend. A Doctor," Eleven repeated, trying to be friendly, "And you… You weren't grown in that tank, were you?" To Amy's surprise, the Thing shook its head, and Eleven's smile faded with sadness and pity.

"What?" Amy asked him.

"He was human," Eleven said, "He still is, in his head."

"You mean, they were experimenting on people?" Amy said, feeling sick. What suffering had the poor man gone through to get like this? And then to try and make his escape, only to be hindered by a lack of communicative skills and an impossible new body.

"Yes," said Eleven, "As I suspected. I saw some files on the floor of that lab, didn't want to mention anything to Fritz, he's one of those people who would put scientific pursuits in front of humanity. Probably wouldn't mean to, but-"

"Like Frankenstein?" Amy suggested.

"Exactly, like Frankenstein," Eleven seemed pleased, "I love companions who read. You're even better, a companion who writes as well. Anyway, this is all very tragic. Those files weren't in good shape after being stepped on by our friend here-" the Thing was listening intently, it seemed, and made no motion to try and leave their company, "-I only managed to catch a few words. Mainly 'soldier' and 'amphibious.'"

"They were trying to create super-soldiers?"

"Undoubtedly," said Eleven with a sigh, "War. Dreadful business, things like this always end up happening. It's interesting how they managed to keep them alive for this long though, unattended. I should think Fritz will be examining the biogel at some point, perhaps it'll help him cure all those diseases?"

"That's something good…" Amy muttered half-heartedly. She felt too sorry for the poor man – whose name she wished she knew so she didn't have to keep saying 'the Thing' – trapped in a fish tank for a century, only to awaken to this further torture. "But what do we do?"

The Doctor sighed.

"I'm not sure. I… I'm sorry," he said to the Thing, turning his attentions back to the rogue science experiment, "I don't think this is a reversible process. I'm so sorry… Are you in pain?" The Thing nodded, and Amy saw sorrow shine through its grizzled, mutated features. The Doctor sighed painfully and rubbed his face once, straightening back up and thinking. "You see the fingers and the toes?"

"Yes."

"It's physical degradation," Eleven said quietly, like he didn't want the Thing to hear but knew he had to let it, "He can't survive outside the tank. None of them can. I suppose that's why they were left here. A failed experiment."

"God…" Amy breathed, feeling ill, "This is awful. What do.. What do we do?" The Doctor said nothing, looking over her head instead of into her eyes, and then looking down at the floor at the feet of the Thing.

The Thing made another crude noise, drawing their attention to it once again. Once it was sure they were watching, it made a move to lift its right hand, pointing its middle finger and the stub where its index finger used to be at its temples, like a gun.

"He wants to die," Eleven told Amy.

"I got that part…" she said in little more than a whisper, "What do we do?"

"The right thing," said the Doctor with darkness in his tone and in his cool eyes that appeared to be looking through rather than looking at anything. Amy looked at him as though to say, 'Which is?' and he breathed deeply again before speaking, "Make it painless."