Rose's body was less acquiescent to the Doctor's wishes. She slept, but her heart continued its irregular rhythm. The dehydration was resolving, yet the arrhythmia persisted.

The Doctor checked her heart for the fifth or sixth time since she'd fallen asleep and found no change for the better. Reluctantly admitting a modicum of defeat, he disconnected the IV line then pulled back the covers and slid his arms under her legs and shoulders. He lifted her easily, certain that she'd lost some weight during the arduous physical ordeal.

"We're taking a little trip now, Rose," he told her softly, but he doubted that she could hear him. "Not far, just a few steps away."

She stirred slightly, eyelids fluttering but remaining closed. He carried her along the corridors and through the open doorway to the clean, white room. He set her gently on the examination couch then quickly prepared the necessary equipment.

He returned to her side wheeling a trolley with a shoe box-sized device upon it. He tapped at several buttons, and an arm rose smoothly from the machine. He positioned the extension over her chest then removed a little remote from his pocket. His thumb hovered over the activation switch.

"Rose," he said, bending down to speak close to her ear, "there's a treatment I need to do—to help you. It shouldn't affect the course of the vaccine very much; at least I don't think it will. And it won't hurt, but you may feel some tingling or itching, and that's all right."

She didn't stir as he rested his fingertips over her heart then depressed the button.

She felt different. She remained too warm, and the achiness continued though the deep pain had receded. But it was something else that had roused her. She moved a hand languidly to scratch at her belly. Her nails raked over the skin, and she flinched in pain.

Her skin was very sensitive—too sensitive. A prickling sensation was dancing over the surface of her entire body.

Rose opened her eyes. The lights were dim, but she could see that she wasn't in her bedroom anymore. Her gaze flicked over her surroundings; she was in the infirmary. When had the Doctor moved her? Her recollections of recent events were somewhat muzzy, but she was certain she recalled his telling her that she was getting better. So what was she doing here?

Something must've happened—something serious enough to warrant the change of setting.

"Doctor?" she croaked, eyes searching the room for him.

There was no response, and within a few moments Rose realised that she was alone. She wriggled as she felt the strange prickling again. She lifted her hand, bringing it slowly to her face. She squinted at it in the dull illumination. The tiny hairs on her wrist and forearm were standing up. But they didn't look as fine as they should; weren't they thicker, coarser? And that sparking through her skin—that couldn't be normal.

She remembered the creature in Sir Robert's barn. Its skin had writhed as it changed, hair sprouting from every follicle. And what must that have felt like? It must have prickled, just as her skin did.

"Oh God," she whispered, eyes widening as the realisation struck her. She was changing. The vaccine hadn't worked; that must be why the Doctor had brought her here. He was probably trying something else, some other medicine or device… like the one positioned over her chest right now.

She itched terribly, and she scratched at her arms and belly again, gasping at the pain these actions brought but unable to stop because the itch was dreadful, and it meant that the transformation was happening. Her fingernails must be turning into claws, sharp and lethal spikes that could maim or kill with a single swipe.

Rose sat up, head swimming with fear. As soon as the change was complete, she'd be a monster, a fiend whose only instinct was to attack any living thing in sight. She had to get away before the Doctor returned. If she didn't, he wouldn't be able to escape her wanton wrath.

She slid down from the couch, feeling the coolness of the floor beneath her bare feet. Her legs were weak, but soon they'd be powerful—powerful enough to stalk through the corridors in search of prey. Rose stumbled from the room, mind reeling as she desperately tried to think of a way to protect the Doctor.

The mugs were almost too hot to keep in his hands, but the Doctor fore bore the discomfort without hesitation. He hadn't felt comfortable waiting for the water to cool sufficiently; he didn't want to leave Rose alone for more than a few minutes. But she'd been responding well to the treatment, heart beat nearly back to normal as the machine regulated the electrical impulses in her body, and he'd thought she'd enjoy a few sips of tea when she awoke. He'd spared only a few extra seconds to prepare a cup for himself, too—his one tiny indulgence, justified by the knowledge that the beverage would fortify his flagging energy. It had been a very long twenty-six hours since he'd seen that little scratch on Rose's side.

He slowed his steps just a bit as he neared the infirmary. There was no need to make any excess noise; he wanted Rose to sleep until she'd regained some strength, however long that might take.

He slipped into the room and set the mugs on the counter. As he turned toward the examination couch, he inhaled sharply. Rose was gone. He moved to the couch, pressing his palm over it to judge whether it still retained any of her heat. The soft fabric was cool; she must have got up just after he left.

She'd probably returned to her room; she'd never been fond of his infirmary. He walked quickly down the hallway and poked his head through her open door.

"Rose?" he called softly. The bed was empty, sheets and comforter pushed aside just as he'd left them.

Frowning, he stepped into the bath, half expecting to find her slumped on the floor. But the small chamber was quiet and still. He ran a hand through his hair, perplexed. Where would she have gone? He'd have passed her in the corridor if she were headed for the kitchen.

Her fever was still high enough to cause some disorientation, and now he worried that she'd become confused as she tried to find her bedroom. She could be wandering anywhere in the labyrinthine corridors of the TARDIS. The lingering results of the illness, too, could have caused her to fall or to lose consciousness, and she could be lying on a cold floor, too weak to rise.

He hurried out to the hallway again and called her name, but there was no response.

He checked all the nearest rooms—the library, the lounge, the gym—but all were untouched by Rose's presence. Frustration and worry washing over him, the Doctor returned to the console room.

Rose shambled down the hallway, panting and sweating, searching for something, anything that would prevent her from harming her friend. She passed the wardrobe room, sparing only a second to glance at the racks of clothing and open closets. She hobbled on, a vague idea forming. There was a room she'd seen once, some sort of storage area, and hadn't there been a vault? That was what she needed—a place to lock herself away, to keep the monster contained for as long as possible, as long as necessary to ensure the Doctor's safety.

She opened door after door, but the storage room eluded her. Her skin was prickling even more, and she was sweating profusely now, and surely that must be a sign that the change was imminent. Her vision blurred to a strange, greenish haze.

"No," she gasped, "not yet. Jus'… need… a little more…time."

She pushed open one more door, and there it was: The large storeroom lay before her. She stumbled toward the vault. The heavy door was open, but she grasped the handle and, using the last of her rapidly waning strength, pulled it shut behind her. It closed with a solid, irrevocable thud. She twisted the interior lock until she heard it click.

Rose sank down to the floor, trembling in terror as she felt herself began to turn into the beast.