Author's Note:

Just for fun! Couldn't resist -- don't know why I haven't done this before...!

ONE

He staggered and shivered, clutching at his burning chest. He felt the brick wall against his shoulder, his eyes squeezed shut, his teeth clenched tightly against the pain.

Shivers ran down his spine. Tiny shocking needles jabbed at every patch of skin. He could feel the blood pounding through his temples, the surges of nausea and dizziness.

His fingers brushed the round button above the names. He grasped the side panel desperately, feeling himself lurch and slide blindly.

"Hello?" came a voice from the small residents' speaker by the buttons.

He opened his mouth but couldn't summon the strength or control to reply. He slipped against the wall, inadvertently dashing his head against the cold bricks. But it couldn't obscure the pain wracking his torso, pushing and pulling at him to double-over, to give in, to fall quietly to the pavement and die in peace.

He wrenched his eyes open and spotted three buttons dancing in his vision. His hand flew out and slapped at them all. Two melted away as the apparitions they were. His fingertips caught at the one on the left. He leaned against it, using it to keep him upright.

"Yes! I can hear you!" came the annoyed shout. "Whoever you are, get your hand off that button or I'll come down there and snap it off!"

He relaxed but left his hand on the button.

"Right! Think you're funny, do you?" There was a long pause. "I'm coming, and you'd better be gone before I open that door and cave your head in with a bat!"

He leaned.

He counted the seconds, feeling the nausea and pain flush over him in waves. He leaned back, his hand losing contact with the button for the first time. His head bumped back against the wall and he staggered, clutching at his chest and wheezing impatiently.

He heard a noise like dragging metal. It didn't matter. The waves of nausea were winning and he couldn't keep them back any longer.

His mouth ran dry, then flooded suddenly with fresh water. He just had time to register the sound of a door opening before he spun to his left. Two hard, round things brushed his palms and he grabbed onto them desperately, the only stable things in his universe.

The entire contents of his stomach were regurgitated in short order, thrown out at high speed and to the accompaniment of loud, unpleasant noises.

"Bloody hell mate!" Martha Jones said from behind him. "What's happened to you!"

The Doctor opened his eyes weakly, not even bothering to attempt to stand up straight. He realised his hands had grabbed his knees, and he was bent over at right angles. He was happy to stay that way until he simply passed out.

Which he did.

Without even turning round.

-------------------------------------------------

Martha sat on the small poof, pulling the heavy blanket up over the insensate Time Lord, currently sprawled out on his back on her sofa.

"Where did he come from this time?" her mother asked quietly from behind her, arranging his blue suit jacket on the hangar behind her door slowly.

"I've no idea," she said quietly. "He didn't call, didn't leave a message, nothing. I had no idea he was coming."

Francine walked over and sat down next to her daughter, looking over the pale alien. "He looks awful. What do you think's wrong with him?"

Martha blew out a long breath, shaking her head slowly. She got up and went to her work bag on the desk, opening it and taking out a borrowed stethoscope. She walked back and slipped it on, pulling the blanket down and resting it on his shirt. She waited, her mother watching her, then moved it to the other side. She bit her lip and moved it around slightly.

"What?" Francine asked worriedly. "What are you looking for?"

"The other heart," she said grimly. "Can't find it. I think… it's stopped," she whispered. She pulled the stethoscope away and looked at the pale face, the pained expression. She looked at her mother helplessly.

"You mean… he should have two working? All the time?" she asked slowly. Martha nodded. "So… What could it be?"

"I don't know, Mum. If he were human, I could think of something. I could take him to a hospital. But he's not. So he's stuck with us."

"That's why he came back here," she said wisely. "To be stuck with you. He believes you can help him." She sighed. "Typical. He only turns up when he needs something, I've noticed."

"Mum!" she protested.

"Oh don't worry," Francine said cynically, "all men do it. They're all the same."

"Look Mum, he –"

He started to cough suddenly and Martha jumped up, grabbing the bucket-shaped bin and rushing back over with it. She was just in time to grab his far shoulder and wrench him over toward the bin, as he brought up an impossible amount of bright blue liquid.

Francine simply watched with calm distaste. She took the bin from her daughter as she pulled him back out straight on his back. She realised his eyes were open.

"I don't even eat carrots," he said weakly, making her smile slightly.

"Hey you," she said warmly, and he began to smile. But then he shivered and hissed suddenly, in pain. "What?" she asked quickly. "What's making you sick? Tell me!"

He gasped and grabbed out blindly, catching the back of the sofa and her knee. He clutched at them painfully, his teeth firmly jammed together and his eyes squeezing shut. Francine moved over quickly, wringing her hands.

Martha watched him relax suddenly, sagging back into the bed. She took his hand off her knee slowly, holding it firmly.

"He looks really bad," Francine said quietly. "He needs proper medical attention."

"Tea," he rasped suddenly, and Martha smiled as at a small child.

"No, mate. We're talking about proper medical –"

"Theanine – blood-brain barrier," he gasped, his eyes closed.

"Oh! Right!" she realised.

"I don't under-" Francine began.

"Mum, do us a favour, get the kettle on," she said quickly, but nevertheless gently.

"Well, if you think it's going to hel-"

"I do," she said hurriedly. Francine looked at her, nodded, and left her to look after the coughing, shivering Time Lord.

Martha waited till the door was shut behind her.

"Mate," she said quickly.

"Martha," he said, sounding more relaxed, but his eyes were still closed. "Theobromine, theanine and…" He drew in a ragged breath. "And lots of polyphenolic antioxidant catechins."

"And that's it? That's all you need?" she asked quickly.

"Heat."

"Right," she said quickly. "And that's it?"

"Trouser pocket," he whispered weakly.

She looked at him. Just looked.

Then she looked down him, finding his right trouser pocket in his blue pinstripe trousers.

"You know, always liked your brown suit better," she said to herself, pushing her hand in. Her fingers connected with something hard and she grasped it, pulling it out. "I'm not even going to ask how this fitted in there," she said with a smile, looking at the silver box in her hand.

It was a five-inch cube with tiny, blinking lights on it.

"Blue?" he asked, pain evident in his whisper.

"There are blue lights on, yeah," she confirmed, and he put his hand up, taking it off her clumsily. He held it firmly, letting it and his hand fall to his stomach, exhausted.

"Right then. You rest and play with your… thing, and I'll get fresh tea," she said, getting up. He let go of the box quickly. His hand clutched at her and she paused, looking at him.

"Martha," he said quietly, opening his eyes. She waited. "Don't let them… stop at the… at the same time," he whispered weakly. She stared at him, her mind racing.

"What?" she asked desperately. "Don't let what stop?"

He opened his mouth but couldn't answer. He pulled her hand down in his, letting it lie on his chest.

"Your hearts!" she realised. "Are they going to try to stop at the same time?"

"Just once," he managed, and she could have sworn she saw the trace of a smile in there. She smiled, squeezing his hand.

"Right then," she said confidently. She put her free hand to his forehead, sweeping his wild fringe away from his eyes and letting her hand rest on his forehead gently, testing the heat.

"Box," he whispered. She picked it up, looking at it.

"What do I do with it?" she asked.

He took a deep breath, and it looked as though he were waiting for an opportune moment to speak.

"Lights. If they go out…" He deflated and gasped in air, albeit in a controlled manner.

"I get it. If they go out, I'm waking you," she said seriously. "Look, relax: I'm on the case," she said kindly, and he smiled slightly but it looked pained. "You have a sleep, shut down, hibernate, do whatever you Time Lords do. Me and Mum will look after you."

"All I…" He paused to suck in a breath slowly, relaxing into the bed comfortably. "…Ever wanted."

She sat and watched him drift into a fitful sleep.