Until three days prior, Donna hadn't known that she did fancy resorts. She had always imagined she'd enjoy it, of course, knowing herself, but she'd never tried. So when she did get to try it, and found that she just might have to stay forever, it didn't come as a surprise. Neither did it surprise her that her mother had been right, the last time she'd mentioned a vacation: it had taken centuries to get to such a lavish place.

It was London, four hundred years in the future. A quick hop forward, as the Doctor had described it, for a much-needed rest—which, for once, seemed to be a genuine rest rather than another of his covert investigations. There had been no trouble, no monsters, no running; nothing but relaxation for the last three days, and there were still two more to go. Donna couldn't fathom where the Doctor had gotten the money for such a vacation—he had paid, so technically she still couldn't afford it—and given his usual reluctance to sit still for more than a few minutes at a time, she suspected the trip was mostly for her benefit. She couldn't be bothered to question him. She was having the time of her life.

Donna had just arrived in the lobby of the resort's hotel, heading back to her room from a tour of the fluorescent gardens. She stepped inside one of the lifts, nerve-wracking glass contraptions that travelled along the outside of the building, looking out over the city, and closed the door with a brush of her fingertips along the wall.

"Floor thirty-eight," she instructed, and couldn't help feeling a little thrill as the lift chimed in response to her command and accelerated rapidly upwards. The sky was black outside the windows—she hadn't realized she'd stayed out so late—and the sprawling city had been transformed into a blanket of twinkling lights, stretching as far as the eye could see.

A resort? In the middle of London? she'd asked, when the Doctor described the place. Aren't resorts supposed to be all tropical with beaches and palm trees?

Not anymore, he'd said, as if it were obvious. This is the future! You can put a resort anywhere. Any attraction you want, right indoors.

It was true—she'd spent a good portion of the day in a building entirely occupied by a beach, complete with waves and a convincing artificial sun.

The lift glided to a stop and she stepped out into a spacious hallway. She reached her own room, a smaller two-story suite with a vaulted ceiling and a whole wall of windows, and pressed her hand to the scanner that unlocked the door.

"Doctor?" she called, closing and bolting the door behind her. She used the touch sensors set into the wall to dial up a couple lights. The doors that separated their joined rooms were flung open, as usual, but there was no response. She could hear a rhythmic clicking coming from the Doctor's room, somewhere around the corner, and she thought she might be able to hear him talking to himself. He was probably absorbed in his work once again.

"Can't even vacation right, that one," she muttered, though she found herself smiling in spite of herself. The Doctor wasn't the sort for lounging around; he'd planned this trip for her, no matter what he said to the contrary, just when she'd been in desperate need of a break.

She dropped her bag on the table by the door and wandered into the kitchen, brushing her hand up the wall to turn on a light. Everything was different this far in the future, as she'd steadily been discovering, not least of all the food. She grabbed a hard-shelled purple fruit from the refrigerator—or, the closest thing to it she had yet found, for it had some features that didn't fit with her idea of a refrigerator—and began the work of peeling it as she made her way to the lounge. Sinking into a plush chair next to the floor-to-ceiling window, she switched on the TV with a tap of her fingers against the armrest. The program played quietly in the background as she popped the membrane-bound pieces of fruit into her mouth, contemplating going to bed early in preparation for tomorrow.

She had just started to relax when she heard a cry from the room next door.

Thoughts of tiredness abandoned, Donna tossed the fruit down on the coffee table and ran to see what was happening. She expected trouble, maybe alien, maybe human; instead, rushing through the doors and into the next room, she found only the Doctor. The alarm she felt gave way to confusion.

He was slumped over the armrest of the sofa, mechanical bits and pieces scattered across the floor around him. She thought he might be dead for a split second, before she realized he must have simply fallen asleep while working. Stepping closer, she saw that his expression was pained, his hand fixed in a white-knuckled grip on the fabric of the cushion. He was muttering to himself, switching rapidly between English and a language she couldn't identify; as she stood over him, he shuddered and let out another muffled shout. This time, she could pick out the word "no."

For a moment she stood there, shocked into hesitation. She didn't know what she was supposed to do. The Doctor wasn't human; it was easy to forget he was an alien, sometimes, but he never seemed quite human. She'd never even considered that he would sleep and dream and have nightmares, though it seemed obvious right then. It was so very contrary to how he presented himself.

Carefully, gently, she reached out to place a hand on his shoulder—but before she could he shot to his feet, instantly alert.

He whipped around, eyes flashing over the room before they settled on Donna, who had frozen with her mouth agape. Fighting to catch his breath as he backed away from the couch, he glanced around the room again like he didn't recognize his surroundings, like he was expecting an attack. Donna took an involuntary step back, startled by his wild defensiveness.

His eyes focused on her and he seemed to snap back to reality. The fear on his face gave way to horror and embarrassment, and he cleared his throat, running his fingers through his hair.

"Donna, yes. Hello. Everything alright?" he asked, in a weak attempt to direct her attention to something else.

Donna gave him a quizzical look, his question taking her by surprise. "Am I alright? Are you alright?"

"'Course. Fine." He looked down at his feet. "Fine."

She breathed a sigh, realizing that he wasn't going to make this easy. "Don't. Don't do that, please." She walked around the couch to face him. "What's wrong?"

He met her gaze and the strength seemed to leave him; he moved past her and sat heavily on the couch. Slowly, unsure of whether she was overstepping her boundaries, she sat down next to him.

The Doctor brushed his hair back again. "It was just a dream," he murmured. "It was nothing, really."

She laid one hand on his arm. "Tell me."

He was silent for a long moment. "I was–" His voice broke, and concern flooded Donna's chest. He was really shaken; it must be serious.

He took a deep breath. "Sometimes I dream about the Time War."

She felt a sinking sensation. The Doctor never spoke about the Time War. She knew he should—and she would listen—but she was only human; she didn't know how she was going to help him.

His voice was rough as he continued, slow and hesitant. "I know I haven't told you a lot about the war, and my home, but… I did fight. That's the reason I survived: I fought on the front lines. And I killed. I–" He pressed the heels of his hands against his eyes. "Oh, Donna, I killed so many people."

He took in a sharp breath and lifted his head to stare at the blank TV on the opposite wall. "The Time Lords had plans for the war," he said, tone even and dull, "plans I couldn't let them go through with. That's why I did it." He turned away, so she couldn't see his face. "I destroyed them all, Daleks and Time Lords and… All of Gallifrey. Gone."

Donna didn't know what to say to that. She knew about Gallifrey; he wasn't telling her, he was reminding himself. He refused to forget, not in times of conflict, nor rest. It seemed to her an obsession, like he was terrified of missing the signs and being forced to make such a decision again. She knew his fears were unfounded—he was the most peaceful, well-meaning person she knew. And though he'd never told her the full story, she knew that he never would have done such a thing if there was any other option. The issue was convincing him.

The Doctor had pressed his forehead against his fist and squeezed his eyes shut, mouth set in a grimace. His breath hitched, and he took his arm from Donna's grasp to cover his face with his hands, nails digging into his skin. He remained frozen, every muscle tensed, for a long moment.

"Doctor?" she asked, alarm stirring in her chest again.

"Sorry," he gasped, dropping his hands. "Sorry, I just–"

Donna took his hand in hers, and realized he was shaking. He was scared.

"It's alright, Doctor, it's all over now. You're safe here. Just… remember that it's all in the past." She squeezed his hand tightly, hoping to keep him present. "My grandad… sometimes he has flashbacks too and, well, it helps to talk about it."

He glanced at her quickly before going back to staring at the floor. "Flashbacks," he repeated quietly, as if the word were new to him. "Yes, right. Quite right. Talking."

"You don't have to," she hurried to add. "I just thought–"

He placed his other hand over hers, and was silent for a minute.

"I dream, often, that I'm watching as Gallifrey's second city is destroyed," he began falteringly.

"It's always the last day of the war, in the final moments, before Gallifrey is… ripped apart. That city was supposed to be invincible, nothing could get through those defences—until the Daleks did. So many Daleks, you couldn't see the light of the suns for all their ships. They broke through the sky trenches and just… demolished everything in their path. Not just soldiers; people, innocent people, civilians. I saw them, being rounded up and shot down in the streets, or crushed by rubble as the Citadel is demolished. Or blown to bits from the orbital bombardment."

There was a silent moment as he steadied himself. "There was this low, constant roar, from all the fires. The heat was unbearable. You couldn't take a step in any direction without nearly being hit by a shot from the ships, and you can hear them whistle as they pass too close to your ear. Everything is so loud. I… I always sort of figured that the screaming would be part of it. But the Daleks…" His expression turned cold. "They really only said one word, over and over: 'Exterminate,'" he spat, lip curled in anger. "That's what I hear: 'Exterminate.'"

Donna felt a chill run down her spine. She noticed the distant look in his eye. He wasn't in the hotel room with her anymore. "It's over now. You're safe here, it's over," she reminded him. "It's alright."

"Is it?" he snapped. "Because it doesn't feel like it."

Catching the startled look on her face, he sighed and drew his hands over his face again. "Sorry, I'm sorry." His voice was raw. "No, it isn't alright. It just isn't."

Drawing a shaky breath, he leaned forward with his elbows on his knees and his face hidden from view, fingers tangled in his hair. "Donna… why did I have to live?" he whispered.

Donna drew back incrementally, heart sinking as she processed the words. "What do you mean?"

"I just–" He sniffed. "I had no intention of surviving that day. I thought I was going to die, along with everyone else, and that would have been okay. That would have been right. But it would have been the easy way out for me. I deserved much worse than that for what I did, and– and I–" A sob broke from his throat, and he hid his face in his hands. "And I got it," he rasped.

Gripped by a sudden surge of protectiveness, Donna threw her arms around him and rested her head on his shoulder. At that he broke down, his resolve to remain stoic disappearing as he returned the hug, holding onto her like his life depended on it. Silent sobs shook his body; she could feel his hearts beating at a panicked pace. Tears stung at her own eyes, and she buried her face in the fabric of his jacket. She wondered, then, how many times he'd woken up from a nightmare with no one to turn to.

"I'm sorry, Doctor," she whispered. "If I'd known–"

"No." He shook his head, and the mask of fortitude was back, however transparent. "No, it's not your responsibility to look after me."

Donna was so taken aback that she leaned back to look him in the eyes. "Doctor," she said, unable to keep the surprise from her voice, "I'm your friend. I want to help you, however I can. You're always helping other people, you never stop. Don't you think you deserve the same?"

The Doctor stared at her, at a loss for words. The look on his face, shocked and ashamed and dismayed all at once, told her all she needed to know.

"Well, I don't care what you think," she grumbled, pulling him into another embrace. "I know you do. And you ask anyone you know, they'll say the same."

Slowly, she felt him wrap his arms around her again. He was still trembling slightly. They were still for a long time, and neither attempted to move until his hearts slowed and his breathing evened out. Then he let out a shaky sigh and met her gaze.

"Thank you," he said thickly. He swallowed hard, and leaned his forehead against her shoulder. "Thank you."

"Don't mention it… spaceman," she added.

He laughed weakly. Letting his arms fall away, he wiped the wetness from his cheeks. "Donna Noble," he sighed. "What would I do without you?"

"I shudder to think." She stood, one hand lingering on the Doctor's arm to make sure he was alright. "Tell you what, you find something good on the telly, and I'll make us some tea."

He gave her a grateful smile. "Sounds good."

As she went to the kitchen and began figuring out how to use the kettle, the Doctor searched for the remote. It was a moment before she got it working and found something to drink.

She sat back on the couch a few minutes later and handed one cup to the Doctor, who sipped it quietly for a minute, watching whatever program he'd found.

"Donna?" he said, after some time.

She looked to him and gave a questioning hum.

"I mean it: thank you."

She smiled. "You are very welcome."