Rose watched, still crying softly but refusing to look away as the metacrisis lowered the Chameleon Arch from the ceiling and snapped a silver fobwatch into a slot on the side with a click. He knelt down on one knee and took Donna from his original self, holding her under the knees and shoulders against his chest. She'd drifted back into unconsciousness, but she was burning up, radiating a bright golden glow.

The two Doctors' eyes met, and the Time Lord gave his half-human duplicate a respectful nod.

"I'll take care of her."

"I know."

His eyes traveled over to Martha, who was standing against a coral strut, bracing herself sadly. She remembered how the transformation process went last time, and she wasn't looking forward to watching it again.

"And…" the metacrisis continued under his breath to his counterpart, "I know you won't remember this, but be nice to Martha. You won't find a more loyal friend than her, and the next year is going to be hard."

The Doctor frowned worriedly at the portent behind his words, but nodded again.

"Are you ready for me to turn it on?" he asked.

"Yeah, do it."

Martha turned away and rubbed her eyes. The Doctor moved towards the control panel.

"Doctor!" the metacrisis called suddenly. It was strange to hear his own voice calling his name. "If… if there's anything left of me… if any part of me does make it through, it'll be in the watch. I… I want Rose to have it."

Rose strangled a sob, and forced a valiant smile. "I'll keep it safe. Forever."

The metacrisis, eyes fixed on Rose, smiled and nodded.

The Doctor threw the switch. Donna and the Doctor immediately began to scream. A rapidly flashing white light grew out from the center between them, and quickly grew bright enough that despite her inner resolution to watch, Rose had to cover her eyes. Donna's and the human Doctor's screams rose together as the agony increased. Martha curled further into the curving wall, wishing she could block it out. The Time Lord at the control panel only watched in stony silence, respectfully bearing witness to his duplicate's sacrifice to save a friend.

After what seemed like an eternity, the Doctor's screams faded and only Donna's remained, shrill but rasping now as her voice gave out. Finally, even that faded and all the lights in the TARDIS flickered and went out.

A few seconds later, the TARDIS usual blue-green glow returned and everyone's eyes readjusted to the light. Rose was the first to dart towards them, throwing herself forward on all fours on the hard grate of the TARDIS floor during the transformation. She reached the center where the machine had been, and pulled back, hands flying to her mouth and fresh tears welling up in her eyes.

Donna lay groaning on the floor, her red hair fanned out over her face. Beside her, there sat a severed human hand, and nothing more.

The machine dinged and a light over the little slot holding the fobwatch turned green. Rose leapt for the empty, hanging device, gingerly detached the fobwatch from the side, took it out and cradled it softly against her chest, heartbroken.

The Doctor, meanwhile, kneeled down next to Donna, who was just coming to. Martha came over to join them and check on Donna's vitals.

"Ughhhh… Doctor?"

The Doctor smiled. "Welcome back."

"You… right… bastard!" she struggled into a sitting position to shout, and then winced and held her head. "Ohhhh, if my head wasn't hurting so badly right now, I would knock you into next week!"

The Doctor raised his eyebrows and hummed admiringly. "That's the old fighting spirit, Donna! Mind you, I haven't actually done anything to deserve that sort of violence yet. Seems a bit premature to threaten me at this point."

Donna narrowed her eyes at him in annoyed perplexity, and looked around. She saw Rose hunched stiffly over something a little ways away and frowned confusedly.

"Is that Rose? What's wrong with her?"

The Doctor fell silent. Since he didn't seem inclined to illuminate the situation, Martha drew in a breath and did it for him. "We… just lost someone."

Donna turned at her voice, suddenly noticing the petite woman on her other side, and then looked at them both in quiet sympathy. "Seems I'm always meeting you just after you lose someone. Who was it?"

The Doctor tugged his ear uncomfortably. "Er, me, actually."

Donna gave him another bewildered look and turned back to Martha. "How does that make any sense? Martha, can you translate for… Ohhhhh." Her eyes widened as comprehension dawned and she fell silent. She remembered leaving Rose with the metacrisis on the beach before flying away with the other Doctor. Now here was Rose, back in this world, with only one Doctor nearby.

"Which one are you, then?" she asked quietly. "Human, or…"

"Time Lord," he answered.

"Then the other one, with my DNA in him…" Donna trailed off, watching Rose from the back. A sense of gloom resettled over the control room, and no one said anything for a few minutes.

Martha broke the silence first in an effort to lighten the atmosphere, or at least move the conversation away from the inevitable question of how he'd died. "So! Another one I haven't met who knows who I am. How famous am I in the future?"

"What are you on about?" Donna asked, brows furrowed.

"Martha hasn't met you yet," the Doctor explained simply, glad of the distraction. "And I've only met you the once, myself."

"You what?" she goggled at him.

"Time travel," said Martha, nodding in a what-can-ya-do kind of way.

"Well, obviously time travel." She looked him up and down. "'S not like you ever change, so there's no telling which 'you' this is. Human, alien, past, future… So if you haven't traveled with me yet, when are you from, then? My past?"

"Yep!" chirped the Doctor.

"After Lance?"

"Definitely after."

"Before Adipose Industries?"

"Never heard of them."

"Then how did you know to come get me? And hold on a minute," she gestured to the Doctor with renewed ire. "Does this mean you-in-the-future knew the whole time that you were gonna come back in your past to return my memories? And you let me think I was gonna die, or get wiped out of existence forever, without even a hint not to worry? 'I'm so sorry, Donna, you can never come back? You can never remember?' I suppose that was funny to you, was it?" she hauled herself up using the TARDIS console for support and pointed at him threateningly.

The Doctor rubbed his hands over his face and tiredly picked himself up off the floor. "Ah, lovely, we're all back to normal." He pretended to have something terribly important to handle on the far side of the room and busied himself toying with some buttons on the opposite wall in an attempt to escape the rest of her rant.

"Oi! You can't walk away from me, mister! I know where you live! And I'm not getting off this boat again without a… a remote control or something so I can bring it back whether you're willing or not, you can count on that!"

She suddenly remembered Rose sitting frozen and isolated like a statue, facing away from them just a few meters away, and lowered her voice. Watching the blonde, her expression softened, and she asked Martha, "Is she going to be all right?"

Martha shook her head, and sighed. "I don't know," she said, concern in her eyes. "I mean, I've only known her a few hours. But it… it didn't go well."

"What happened to him?"

"He wasn't…" Martha shifted uncomfortably, trying to think what might be the most tactful way to answer without putting any undue burden on Donna. "He said he was an extra, and she could stay with him." She jerked a thumb over her shoulder to indicate the Time Lord on the other side of the room. "Then he just sorta… disappeared into the Chameleon Arch."

Donna's gaze on her held steady. "You mean he sacrificed himself again. For me, this time."

Martha pressed her lips together and nodded.

"That stupid, alien git. I would smack 'im one if he…" She looked down at her hands. "He didn't have to do that. There had to have been another way."

Martha shrugged dispiritedly, not knowing what to say.

"An' I suppose he waited for the last minute before telling anyone what he was planning!" she continued, drawing herself up indignantly. "Typical! He thinks he's some kind of god of the universe, can make all the decisions for everybody, all on his own, but he isn't half clueless most of the time."

While the two companions got acquainted, or possibly re-acquainted, the Doctor slowly circled back to the console and wandered over to the viewscreen to assess their situation in the vortex. Right before they'd taken off, he'd sensed thousands of other Time Lords, and then the TARDIS had alerted him that the time vortex was about to be closed off to all time travelers, something that could only be done with the Eye of Harmony. He didn't see how it could be possible, but somehow, Gallifrey must have come back. That would definitely explain the weakening of the walls between parallel worlds. Time itself would have had to have come undone for such a thing to even be possible.

Now, however, as he monitored the time vortex and experimentally entered various time-space coordinates, he could see no sign of a vortex lock or even any damage to the time-space continuum. The breaches between universes were perfectly sealed. It was as if Gallifrey had never even existed, which, if the Time War and its combatants had somehow been returned to the time locked pocket dimension he'd forever trapped them in, would technically be true.

He shook his head, telling himself to stop thinking about it. He would find out about it soon enough, as soon as his personal timeline caught up to where his future self was in 2009. He would be there, had been there, and had clearly done something to stop it. While that in itself was somewhat reassuring, the whole fact that it had happened at all left him deeply unsettled. But he couldn't get involved, not without crossing his own timeline and potentially setting off a paradox that would unravel the entire universe. He'd have to leave it alone, and cross that bridge when he came to it. He had problems enough here in the meantime.

He turned back from the computer screen and looked at Rose. She stood motionless before the Chameleon Arch control, still staring fixedly at the fobwatch in her hands with her back to the other occupants in the room. Her eyes were hidden by her fallen hair, but her whole demeanor was that of a woman completely and utterly lost.

He itched to comfort her, but stayed where he was, tugging his ear awkwardly instead. They needed to talk, but not with Martha and Donna hovering around and her lover's disembodied corpse hand lying on the grate a few feet away. Best to get the TARDIS somewhere safe first, let out the other passengers, and just confirm that the timelines were really secure again.

"Looks like the vortex lock is gone," he said lightly to the room in general. "I'll just bring her down back where we left, 2007, have a quick look around, see that the timelines are intact, that sort of thing."