A/N: Hello again! So, not quite as long a wait between chapters this time, but still not quite good enough, right? Sorry about that- I had my AS drama exams last week (which went very well, thank you for asking), so I haven't really had time to write this. I've cobbled together quite a long chapter as way of an apology :')

I'd also like to say thank you to you all for reviewing/ favouriting/ alerting this story. I don't often say it, but it really does make my day that so many people are enjoying this. :D

Almost an hour had passed since Jenny left William behind in the last task, and he still hadn't emerged through the door. Not that she cared any more. Her number one priority now was healing her face and neck before the injuries got so bad that she couldn't fight off the recurring tingling of an oncoming regeneration and just exploded in a golden hue all over the place. She wondered how she'd managed to hold it off this long- she'd never been able to before- but quickly put it down to her determination that nothing was going to slow her down now. She wasn't like a normal Time Lord; she didn't regenerate like the Doctor. After the initial burst of golden energy, it could take her up to a month to fully change appearance. A full month that had her completely incarcerated the entire time. She couldn't afford to waste that kind of time.

Her hands shook as she rummaged through the boxes of supplies left for her in the resting bay, searching desperately for something that might take the pain away from her injuries. Her sight and hearing still wasn't great, so that didn't help matters at all, but she knew her body well enough to realise that that wasn't the reason for her quaking. She was afraid. Afraid that she could no longer control her anger (the trashed resting bay was evidence enough of that), afraid she'd regenerate and lose time, afraid for the Doctor's sake, and, most confusingly of all (which only caused more fear to take hold), afraid that, now she had calmed down a bit, she had done the wrong thing by leaving William behind.

No, she told herself firmly, tugging a packet of industry strength pain killers and a tube of, what she assumed was, healing cream from the bottom of the only crate she hadn't yet destroyed in her earlier fit of rage. William is weak. They all were. That's why they're dead, and you're still here. It's survival of the fittest- just a difference in genetics. The strongest survive, end of.

She ripped the packet of painkillers apart and stuffed a handful into her mouth, swallowing painfully hard, before smearing the tube of paste across her face and neck. There was no one there to judge her, so she really didn't care how stupid she looked.

Taking a deep breath, she got shakily to her feet. A part of her desperately wanted to give up and sit down, but she ignored this part of her (the sensible part) and moved over to the next door at the far side of the room. If she could just power through the pain, she was certain that she could survive on adrenaline alone long enough for her body to repair itself without the need for regeneration. At least, that's what she hoped.

Her head was already fuzzy from the, most probably, dangerous amounts of pain medication she had taken by the time she got to the door. It took a few moments of staring at the solid surface to realise that there was something different about this door… There was writing on it! Jenny squinted, willing her eyes to focus properly so she could make out the words on the door.

Sink to swim.

Was that it? Jenny tilted her head like an inquisitive dog, hoping she'd understand the words better from a different angle. Nothing. So what was that supposed to mean? She found she couldn't quite think properly, and cursed herself for swallowing so many pills.

Figuring that she'd soon find out what the riddle meant anyway, she took a deep breath, reached out, and pushed the door open. It swung open with a creak, and only darkness lay beyond.

"Well, no time like the present," Jenny muttered to herself, before stepping forward into the room.

As soon as she crossed the threshold, she had to dodge the door as it slammed closed with a dull thud behind her. There were a number of clicks, and it became apparent that she'd been bolted in. Brilliant.

As with the other two challenges, torches flared into life as she stepped into the centre of the huge, cavernous space. This room was easily as large as the first, if not bigger, but without the homicidal octopus on the ceiling, she realised with a sigh of relief upon looking up. There was, however, another door placed in the wall at least fifty feet above her, just below the ceiling. There was also an old fashioned, pirate-ship-wheel-esque crank in the same place as the door on the opposite wall.

"Well how in the name of sanity am I supposed to get up there?" she asked aloud, frowning.

She stood, pondering her options for a few minutes in complete silence, before there was an unexpected bang from somewhere behind her. She rotated quickly on the spot, bringing her fists up to protect her from whatever beastly force was being thrown at her now. She was, therefore, shocked to see an all too familiar figure stood by the newly closed door.

"William?" she asked, slightly shocked. She had assumed that, by now, he would have been blown apart in the last challenge, just like the others. She found that she wasn't angry with him anymore, though. The fury that had burned inside her only an hour ago had now been extinguished, and replaced with pain and exhaustion.

"You seem surprised," he spat in reply, stepping across the huge space towards her. As he passed through a patch of torch light, contempt burst from his eyes. "What? Did you think I'd been blown to bits?"

"Honestly? Yes," Jenny replied truthfully, watching the young man warily as he strode purposefully towards her. She didn't like the way he was looking at her. "If it's any consolation, I'm sorry. I had to get away- it was too much. It was either leave you or kill you myself-"

"-SHUT UP!" William screamed, swiftly stepping in front of Jenny and bringing his hand round to strike her across the face. She fell away, reeling. "All you ever do is talk! And at first I trusted what you said- when you said we should stick together, it made sense. I thought we'd be stronger together, but getting to know each other just made us weaker! It just made everything more difficult when they died. And that's your fault!"

Jenny looked up from her place on the floor, rubbing her quickly bruising cheek in shock. She wasn't going to pretend that she knew William, but she had certainly never seen this side of his character before. He had always seemed so calm and gentle- so well put together- that, honestly, she was a little frightened.

"William, I-"

"-NO! IT'S YOUR FAULT THAT THEY'RE DEAD," he screeched, face set. "And I can't bring them back… but I can avenge them!"

Jenny barely had time to process this before William had launched himself on her, punching and kicking every inch of her that he could find. She didn't fight back, just tried to protect her already aching face as best she could.

"William! Calm down, for god's sa-"

The wind was knocked out of her as William thrust his knee into her ribs, and she didn't finish her sentence. She tried to roll away from his onslaught, batting him aside, but in the process one of her flailing fists connected with his jaw and he fell away, crying out in pain. This gave Jenny just enough time to pull herself shakily to her feet. She had to hunch over; the pain in her ribs meant she couldn't straighten up properly, and she clutched her middle tightly with a protective arm. She reached up with her other hand and wiped something sticky away from her nose. It was blood.

Neither of them spoke for a few, tense moments. The only thing that kept them from lapsing into complete silence was the sound of their ragged breathing. William slowly clambered to his feet, panting, and the two stared at each other from across the room. Neither moved, simply choosing to gage the other's reaction to the sudden change in dynamic between them.

"Look, William," Jenny started, taking advantage of his silence, "I know you're upset, and grieving, and you have every right to be angry with me-"

"-You're doing it again!" he yelled, gesturing incredulously towards her. "You think your words make everything better, but they don't! How can you possibly justify what you've done with words? How can you justify it at all?"

"It's not my fault!" Jenny snapped, feeling her anger begin to rise again. "It's not my fault that humans are too stupid to listen to instruction! It's not my fault that any of them were here in the first place! It's not my fault that you've been acting like a child- if you knew you wouldn't be able to handle screwing people over to get what you want, why did you come here in the first place? You're just projecting your own guilt onto me, but you have no right- none whatsoever- to do so! It's not my fault that you're weak!"

"Weak?" William was quiet now, and, in a way, it was even worse than if he had screamed at the top of his lungs. "WEAK?"

He surged forward, but this time Jenny was ready for him. Grounding herself by planting her feet firmly on the floor, she opened her arms and received William as he threw himself at her, using the power of his blow against him and throwing herself on him as he lost his balance whilst slamming into her chest. They both went hurtling to the floor, Jenny landing on top of William, and her hands immediately found his throat. She squeezed, hard, and William coughed violently, choking. His fingernails scratched at her hands, trying desperately to get her to let go, but Jenny ignored it. He was turning blue.

"Is this how you imagined you'd die, then?" she growled, leaning right in so their faces were almost touching. She wanted to make sure she was the last thing William saw before he died. "Blackness creeping into the corners of your vision; throat burning, craving the air that's all around you- the air that you can't have?"

William's eyes flickered, and Jenny took great pleasure in watching as the life slowly left them. His struggling was becoming weaker and weaker- his hands shaking and body going limp.

Then, quiet suddenly and completely unexpectedly, a grating roar shook the whole room and Jenny instinctively looked up, expecting to find another octopus hanging from the ceiling. Instead, she was met with a wall of water that had come crashing through a newly made opening in the wall to her left. Her grip on William slackened and she had just enough time to yell out in surprise before she was swept away from him completely and submerged in an icy cold sheet.

Her back hit something hard, and she realised the force of the water quickly filling the room was pinning her against the wall- the current pressing the air from her lungs. She didn't struggle; a half-formed memory sparked in the back of the head telling her to wait until the room was fuller so she could propel herself through the water to the surface more easily. The torches had been extinguished by this point, so she couldn't tell where William had floated off to, or whether he was even still alive. All she could hope for was that she could hold her breath long enough to pull herself out of the current.

The cold of the water was beginning to seep into her bones, constricting her lungs and windpipe even more, and the lack of oxygen was beginning to take its toll on her. She looked up, seeing the surface was now at least halfway up the room. Steeling herself against the cold, she kicked out against the, now, weaker current, and used her hands to guide herself up the wall and towards the promise of air. She'd be able to relax and move at her own pace once she got above the hole in the wall behind her that water was still gushing from; the current seemed to be flowing down towards grates in the corner of the room that she hadn't noticed before now.

Jenny's head broke the surface and she sprayed a mouthful of water out of her mouth and nose, before gasping aloud with a sudden intake of air. Her lungs ached and protested, but the chill of the water was doing her burns a world of good. Relief washed over her in the knowledge that- for now, at least- she was safe. Well, as long as she didn't freeze to death or drown before she figured out how to get out, anyway.

"William?" she cried, voice horse, as she spun in the water, trying to spot any sign of him. "William?"

She couldn't find him. The surface of the water swirled ominously around her, but she couldn't make out any sort of body shape floating around amidst it. She kicked out into the centre of the room anyway, squinting through the darkness to try and find the boy. The sudden blast of icy cold spray had shocked the fury out of her, and now all she felt was worry.

"William? If you're here, just shout! Give me some sort of sign- any sign!"

She got no response, as she had assumed. Sighing in frustration, she span in the water once more to make sure she hadn't missed anything (though, in the dark, there could have been a ten foot banana a few feet away from her and she wouldn't have been able to see it), before propelling herself back towards the wall. She was almost there, when she felt something snake around her foot. Jumping in surprise, she tried to tug herself free, but whatever was holding her wasn't letting up. Thinking quickly, she took a deep breath and dipped her head under the water. It took her eyes a few seconds to adjust, but eventually a lanky body swam into her view. William's eyes were wide and fearful, and he was flailing about without really going anywhere. He couldn't swim.

Without thinking, Jenny plunged fully into the water and hooked her hands under William's armpits. He fought at first- probably thinking that she was trying to attack him again- but his attempts to get away got weaker and weaker as his lungs screeched for air. She didn't know how he'd managed to hold his breath even this long, especially seeing how he'd been so short of breath before the water had even come crashing down on him.

Jenny gave a forceful tug, and kicked desperately with her legs to keep treading water and hold William's weight as she propelled them both back towards the surface. She pushed William up ahead of her, and his head broke the surface before hers, but she soon followed, gasping for air once again.

"Are you alright?" she asked, still gripping William tightly to avoid him plunging below the surface again.

"No! You tried to kill me!" he cried, kicking wildly to try and keep himself afloat.

"Yeah, well, you made me cross!"

"Cross? Cross enough to kill me?"

"Look, I tried to warn you- I told you that I left you because I couldn't cope, that it was leave you or kill you! What can I say? I'm a bit unhinged…" Jenny shrugged, brushing William's incredulous expression aside. "Look, I know you're a bit miffed or whatever, and I can understand that, but we can still both get out of this. All we have to do is complete this task, and then we never have to see each other again. Deal?"

She watched William's reaction carefully, very aware that he could quite easily go mental again and try to drown her. A similar thought seemed to cross his face for the briefest of moments, before his whole body relaxed and he sighed.

"Alright."

Jenny smiled. "Brilliant. Right, first things first- can you swim at all, or am I going to have to keep hold of you the entire time?"

"I live in a city- why would I ever need to learn how to swim?" William asked.

"For cases similar to this, I imagine!" Jenny cried.

"Yeah, well, I don't plan on getting myself into something like this ever again, thanks."

"Right," Jenny sighed, frustrated. "It's fine that you can't swim. I can keep a hold of you long enough for us to rise to the ceiling, so long as you keep kicking your legs with me to help keep us afloat. Sound fair?"

"Yeah," William nodded, "But what do we do once we rise to the top of the room?"

"I assume we have to wind that wheel up there to get the door to open, and then flow out into the next room with the water."

"Well that doesn't sound too difficult," William scoffed.

"Says the guy who can't swim…" Jenny muttered under her breath.

Luckily for them, the water level rose exceedingly quickly, but that didn't reduce the cold that was quickly stiffening their muscles. By the time they were in reach of the crank, both were shivering violently and Jenny noticed that William's lips were blue.

"Alright," she spluttered, guiding William over to the crank and allowing him to cling to it. "We wind the wheel, and when the door is open wide enough for us to slip through, I'll signal to let go and the current of the water flowing through the door should take us with it. You'll have to hold your breath, but we'll move that quickly that it should only be for a couple of seconds."

William nodded, unable to talk as he was so cold. Jenny was coping better, what with her advanced Time Lord genes, but she could tell that he was really beginning to struggle. She had to get him out of the water and into dry clothes as soon as possible.

"Ok, let's go," she breathed, before moving up beside William to begin turning the crank.

She could tell it was working immediately, as her legs were tugged towards the door which now had a steadily growing crack in it as it slid open, and braced herself against the crank to get a tighter hold as she and William pushed. Only a few more winds and…

"Now! Let go!" she cried as the door slid open wide enough to fit their bodies through it. She dropped into the depleting water and heard William do the same, before she was dragged along by the current towards the exit.

She closed her eyes, content to let the water take her to safety, and was therefore shocked when her back, once again, hit something hard. Her eyes snapped open and she span, only to realise that the door had slid shut again as they'd let go of it. Anger flared in her as she realised what that meant.

Snatching hold of a thrashing, panicking William's arm, she pulled him along with her back to the surface, and took yet another deep breath as she came up for air.

"What happened?" William cried, spitting a mouthful of water out as Jenny carted him back over to the crank- water now refilling the room through the still open patch of wall below them.

"The door slides closed when we let go of the wheel. It must have to be held in place to keep the door open for any length of time," she replied.

"Well there must be some way of holding it. Maybe we can jam it with something or-"

"-I was wrong, William," Jenny breathed softly, stopping the boy in his tracks and surprising even herself.

"W-what do you mean?" he asked after a short pause, suddenly confused.

"Only one of us can win," she replied slowly, suddenly defeated. "One of us has to stay and hold the door open, while the other is carried through by the current."

And there it was- the final task. A test of emotional strength. One of them had to prove their bravery and selflessness by staying behind, while the other had to be strong enough to live with the knowledge that they had allowed someone to die for them. It seemed, either way, neither of them were winners now. One would walk away a haunted person; the other wouldn't walk away at all.

"No," William muttered, shaking his head stubbornly. "No, that can't be right. There must be something we can do- come on! You've always got an answer for everything; there must be another way! A way for us both to get out!"

"There isn't."

"Well, I don't believe you," he told her firmly, reaching out to grab hold of the crank again. "We just have to open the door all the way- it'll give us more time to get through."

Jenny admired the never-say-die attitude William seemed to have suddenly adopted, but she knew his efforts were fruitless. She realised that she had always known- a simple calculation told her that the room was just too large to allow them to pass through the door in the allotted time before it slid closed, even if it was fully open to begin with. One of them had to die, and, with heavy hearts, she realised it had to be her. William stood no chance of surviving in the water much longer- he would freeze to death before he even drowned- but Jenny could regenerate. She could get William out and possibly (probably not) still save herself in the process.

But even if she did regenerate, she'd still be in a room filled with water. She'd just keep drowning over and over again until she eventually ran out of regenerations, or her body couldn't take it anymore, or whatever happened in these sorts of situations. Had this happened to a Time Lord before? She doubted it.

She realised that William had started to wind the wheel, and reached out quickly to grip it. She wasn't letting him trick her into being pulled away by the current!

"William, stop," she told him quietly, but firmly. A look of pure concentration had come across the boy's face, and he ignored her. "William, please, listen to me."

"No," he replied shortly, still winding.

"William, really, it's alright. I'll stay behind-"

"No! We can both go home; we can both get what we want."

"We can't, William, and you know it," Jenny murmured sadly. "You have a family to think about. You need to go home to them."

And, sighing shakily, William finally came to a stop. The door was now half open and water flowed through it, but they both clung to the crank for all they were worth.

"I just… I can't go back by myself," he whispered, looking directly at Jenny. "The Earth needs to know what goes on here, but I… I'm not strong enough to tell them. I know I said some things, but you're so much better at talking than I am. You'd be able to make them understand; make them stop sending others here. I need you with me."

Jenny sighed heavily. He wasn't going to budge of his own accord. She didn't even know why she wanted him to. Probably because she had finally let her barriers down, and all the guilt and grief over the others' deaths was starting to grind on her. She couldn't let William die, too. She just couldn't. So, she did the only thing she could think of.

"William, there's something I need to tell you."

"What?" he asked, brow suddenly furrowed.

"I was the one who let the bomb off on the space station. I'm the reason your father's dead."

"What?"

She told the truth.

She watched as William's grip on the crank weakened in shock, and heard the splash as he slipped and fell into the water below. Clutching the crank as tightly as she could, she saw his form get washed along with the current, and then disappear from sight through the door.

The next thing she knew, she was in the water, and realised she must have let go of the wheel at some point. She didn't even make it halfway across the room before the door slid closed, and she came to a calm, resigned stop, floating on her back with her face to the ceiling.

She was alone.

A/N: So there you are! I'm thinking one more chapter, and then I'll do another Doctor/ Pond one. Sound fair? :)

R&R? Thanks guyssss x