The TARDIS was scanning for him, looking up his most recent companions. Surely he had time, if he hurried, to stop by and see them all. No long conversations or lingering goodbyes; just to see them once more, with this body, these eyes. Let them know they hadn't been forgotten.
The Doctor looked over the list the TARDIS presented to him. Mickey and Martha--together, hm, that was something he hadn't seen coming. In danger as usual. That would work. His last gift to them, and they'd be too busy to want him to stay and chat. Donna's wedding, that was good as well, he could see Wilf, see Donna's happiness for himself, and then he could--
He checked the estimated timeline again and sighed. No. Even if he didn't linger, there wouldn't be time for these last visits, not now. He'd known what he had to do the moment he saw the Master, silhouetted against the last explosion of light. The Master falling, his faulty body's energy depleted.
Most likely he hadn't survived that. And even if he had, it was highly unlikely that Rassilon would have let him live very long once they were Time-Locked again. It didn't matter. If there was even the slightest of chances, the Doctor had to try to save him. And he had to do it now, while the vortex was still disturbed by all the reality tampering that had taken place here. The longer he waited, the more it would distort the time-stream later.
Regretfully, he looked at the list again. He had all of time and space to catch up with Jack, and Jack, after all, never had cared which face he wore. He could fix up Donna's wedding present any time--had it all planned out already, as a matter of fact--and maybe it would do Wilf good to see that the Doctor did go on, in one shape or another.
Mickey, Martha, and Luke were the only ones he needed to see. He'd pinned down their locations to a certain position in space/time; now he was responsible for their safety at that time. The others could wait.
His eyes lingered on the last name on the list for several moments before he deleted all but two destinations. He'd really wanted to see her once more. To see her before she knew horror and death and the Time Vortex; before she became a warrior for Pete's Torchwood. But giving her even a glimpse of him in this body? Probably a bad idea for the timeline. He could always do it later. One day. Maybe.
He set the TARDIS to land near where the Sontaran would be taking aim at Mickey and Martha, and scribbled a hasty Post-It note to remind himself about Donna's wedding present. He also added a reminder to talk to Wilf. As the TARDIS materialized, he wrote "IMPORTANT!" in the Gallifreyan equivalent of all-caps, and circled it for emphasis. He knew himself too well, and one of the ways he tended to deal with the discomfiting sensation of becoming another person entirely was to shake off most of the associations and relationships he'd made in the last body. He'd gotten slightly better at it lately, but one couldn't take anything for granted. Wilf deserved better than to be lost in the shuffle.
He grimaced, bracing himself against a surge of regeneration energy that coursed through his body, and then quickly exited the TARDIS, clutching the sledgehammer that he generally used for percussive maintenance.
That was Luke sorted out as well, then, and he'd even got to see Sarah Jane. One more rescue, now, if he could pull it off; one more last-ditch effort to save someone who might not have needed saving if not for him. Now, if he could just remember where he'd tossed the Key to the Time Lock before regenerating the last time...
The TARDIS didn't want to tell him. She sulked and pretended not to hear, then pretended to have forgotten the Key entirely. It wasn't so much that she didn't want to go back to Gallifrey, as that she didn't want the Master anywhere near her. He understood that. Under normal circumstances he'd have soothed her, promised to protect her, but he didn't have time for that now.
"Oh, come on, you've got to help me!" he shouted frantically. "I have to do this now, before--" Before the disturbance they created disappeared, of course, but also before he regenerated, because even though it wasn't logical, it was this body the Master had rescued, and he felt somehow that it should be this body that returned the favor--
--and he straightened up, clutching at his hair and grinning wildly, because he'd had an Idea, and it was brilliant, it really was, it totally deserved the capital letter. Brilliant or insane, one or the other, and it was even chances whether they'd both end up dead at the end of the day or not, but it was the only plan he had, and he was running with it. If he could just find the Key.
He finally sweet-talked the TARDIS into "remembering" where the Key was, and he expended far too much energy opening the Lock quietly and sneaking in, leaving the TARDIS set just out of sync with Gallifrey's timeline. And wasn't that a job, when Gallifrey's timeline itself was out of sync with all of reality, fractured and folded in on itself and splintering. It was worse than when he'd escaped, he realized immediately; whatever they'd been doing in his absence was only serving to destabilize the loop keeping them in place. Unless they got themselves under some sort of control, Gallifrey was going to fall out of existence not only outside the Time Lock, but inside as well.
The thought didn't rip at his insides as it once had. He'd done this once before, he'd grieved for them and learned to think of them as if they were dead already, and he didn't have the time or the energy now to go through it all again. He'd tried to save them all and failed; if he were very lucky this time, he might save one of them.
The biggest flaw in this plan, if it could even be dignified with the term, was that he had no idea how to find the Master, or if he was even still alive. He could hardly stroll up to the first person he saw and--
Well, perhaps he could. He beamed at the woman who'd come out of a side corridor. "Madam! Er, I'm sorry, we weren't formally introduced. I'm the Doctor, obviously, and you...you're not Susan, by any chance?"
She pulled him into an alcove. "I am the Lady Nussa. I am pleased to see you again, Doctor. I know why you are here. I have been waiting for you."
"Nussa?" He looked at her in disbelief. "No. Really?" Well, most Time Lords didn't speak English, after all, so most likely they'd never noticed the...coincidence. "Definitely not Susan, then?"
The woman gave him that look again, that strange mixture of sadness and pride that he'd seen during the confrontation with Rassilon. "That would be impossible, Doctor. Susan died on Earth, in an alternate future. And even if she had survived, somehow, and made her way back to Gallifrey...she would have been most unwise to admit to her heritage, given the current political climate."
"I understand. That's a shame, then. Because Susan--she was my granddaughter, and I lost her. Well, I didn't lose her, exactly. I left her. I'm good at that, you know. Leaving people." He swallowed, ducking his head, aware that he was rambling but unable to stop. "I thought it was best for her. I think I've learned some things, since then, and maybe...but it wasn't because I didn't care about her, and I wish I could have told her--"
The whole building shook slightly, and the woman seized his arm. "Quickly, Doctor, you have very little time." She smiled back at him as he followed her obediently. "If Susan had lived, I'm sure she would have known all the things you wanted to say to her."
He nodded, his throat tight, and she stopped by a door in the wall, indistinguishable from any of the others. She took a key from her pocket and pressed it into his hand. "He's alive, but only just," she whispered, looking up and down the corridors. "Rassilon would have killed him, but he was so weakened by the Master's attack that he was drawn into the Eye of Harmony upon his return here."
"Drawn into the Eye?" The Doctor raised his eyebrows. "I didn't realize that the Eye was acting on its own these days."
"Many things are not behaving as they should in these times, Doctor," she said calmly. "Actions are having unexpected consequences. Rassilon's...enforced recuperation...may give the Council some time to examine its options, to decide whether the Time Lords wish to continue on the path that he has set." She shrugged. "You had better hurry. I am shielding you from their scans, but I cannot do that indefinitely. Go."
The Doctor looked at the key in his hand, then blinked at it. He pulled out his glasses, put them on, and looked again. "Wait, this isn't--"
"It's not an ordinary key, no. I've time-locked him--"
"A lock within a lock? But that's--"
"I know," she said fiercely. "But he was nearly dead, he never would have survived more than a few minutes, and I'm so sorry, Doctor, he's in so much pain and perhaps it would have been more merciful to let him die, but--"
He squeezed her hand in sympathy. "It's hard, isn't it? Knowing the right thing to do. I'll do the best I can for him."
She glanced around again. "He won't last long outside the lock. You have only a few minutes. Use them wisely, Doctor."
He had only a few minutes in more ways than she knew. "Lady Nussa, thank you. This means everything to me. And you--surely you don't want to stay here, with these madmen? I can take you as well--"
"I'm needed here, Doctor." Her eyes were wet as she smiled up at him. "With Rassilon gone, there are more power struggles than ever. They are tearing each other apart. Perhaps I can be a voice of reason, perhaps one day the Time Lords will be fit to enter reality again--"
"Oh, very nice streak of unwarranted optimism you have there. Dunno where you picked it up." The Doctor sighed, and she threw her arms around him suddenly, hugging him tightly, but before he could respond, she had let him go and was hurrying away, down the corridor.
The Doctor blinked rapidly, watching her go, and then turned to the door. Opening it was a complicated dance between the physical and the chronological mechanisms, and by the time he stepped inside the door he had to lean against it, pushing it closed as he fought off another surge of regeneration energy. It was building up, getting stronger. He wouldn't be able to hold it off much longer.
He straightened after a moment and went towards the Master, who was lying on a simple cot that was the room's only feature. Well, he wouldn't have needed anything else, after all, as technically speaking he was living the same few minutes in this room over and over.
The Doctor realized suddenly that he hadn't thought to ask not-Susan-at-all how long, subjectively speaking, the Master had been here. Not that it mattered much, really, he supposed.
He shook the Master's shoulder gently. The Master erupted awake, snarling, doing that X-ray trick again, the one that gave the Doctor a sick feeling in his stomach just looking at it, and he stepped back quickly. "Sorry! Sorry, didn't mean to startle you, it's just we need to get out of here right away, and--"
The Master was flickering back and forth between normal and skeletal more quickly than the Doctor could follow, and he started to get dizzy watching him. Not-Susan had been right--the Master couldn't survive more than a few minutes like this. His body was tearing itself apart.
The Master sat up, still growling, and swung himself off the bed, baring his teeth at the Doctor. "He hates you!"
"Well, that's fairly--wait, who does?" The Doctor frowned at him.
"He hates you," the Master repeated. He was looking right at the Doctor, but clearly not seeing him; his gaze was focused on something else, something the Doctor could only imagine. "He's inside my head, all the time, pounding, pounding, he hates you, he wants you dead--"
He raised his hands, his face twisting, his fingers curling in that already-familiar motion, and the Doctor lunged forward. "No, stop, you can't! You don't have any energy left, you'll kill yourself!" He grabbed the Master's hands, forced them down.
"Renegade," the Master spat, but he'd stopped fighting the Doctor. "Traitor--worthless--"
"Yes, all right, all of that," the Doctor said desperately. "You can kill me later, okay? Let's just...go back to the TARDIS and you can take your time about it, right?"
"He wants you dead," the Master said again, reflectively, and the Doctor let go of him carefully. "I don't think I do. Maybe...I can't remember now."
The Doctor stared at him for a long moment, before another surge of energy made him double over in the effort to hold it back. "You have to come now," he pleaded. "We'll both die here if they find us!"
The Master smiled at him, and it was such a sweet smile that the Doctor's hearts ached for him. "I'm going to die anyway," he said matter-of-factly, but when the Doctor grabbed his hand and pulled, he followed docilely enough.
For a moment he didn't think either of them would make it through the time-lock. The Master stiffened and went skeletal for several seconds, but the Doctor couldn't worry about that because his own body began glowing gold all over. "No, no no no no no!" he shouted, in total disregard for anyone who might hear him. "Not now, not yet!"
It was stubbornness alone keeping him going now, he knew. He looked up, breathless, just in time to see the Master flicker back to something approaching normality and look at him curiously. "I know you. Why are you here?"
"Still bone-dead stupid," he muttered. Movement at the far end of the corridor caught his eye, and he whipped his glasses off to look. Funny hats and red robes, and wasn't that exactly what they both needed right now? The Master turned and grinned manically, thrusting his hands out to aim, and the Doctor grabbed his arm. "No! Run!"
It wasn't far to the TARDIS, and he'd never been happier that he'd installed that remote control than he was at the moment that he clicked the button and she shimmered back into sync with them, and the door opened just as they threw themselves against it.
He locked the door behind them and staggered up the ramp to throw the switch that would send them into the Vortex. Maybe he should tie that into the remote too, might come in handy someday. The Key was still hooked into the console, set to warp time around them as they dematerialized, locking Gallifrey away again. "Too many locks," he panted. "Too many keys. Too much kept apart, kept separate. Mine. Yours. Theirs."
He winced as the golden glow raced through his body again. Holding it back had become mental agony as well as physical now; the time vortex knew that he was past due, knew that he was wrong, that he should be different now. He'd dammed the regeneration energy up like a river, and it was about to sweep over him. He only hoped that he'd waited long enough, that the tidal wave would be strong enough for what he wanted.
He turned to see the Master standing by the door where he'd left him, watching him with wide eyes. "You're glowing," he whispered.
"I know." He went back down the ramp. Even walking was almost impossible by now. He was holding this body together through willpower alone, and moving it without letting it go took all the mental energy he could summon. "I'm regenerating."
The Master flickered back and forth rapidly, like an old movie nearing the end of its reel. "I can't do that. This body is broken. It won't work."
"I know," the Doctor said again. He looked up as the cloister bell began tolling throughout the TARDIS.
The Master looked up as well. "She doesn't want me here," he said anxiously, and then he flickered again and his mood changed just as quickly. "They didn't want me either! They made me, and then they left me to die!" He flung his arms out wide, lightning sparking in his palms.
"No!" The Doctor grabbed wildly at the Master's shirt, overbalanced, and fell, pulling the Master down to his knees as well. "I want you here. And I'm not going to let you die."
The Master gripped the Doctor's shoulders so tightly that it was painful, searching his eyes. "I can't regenerate. You asked me to, and I wouldn't, and now I can't." His voice was ragged, desperate. He'd always been too afraid of death. The Doctor was beginning to wonder how much of that was inborn, and how much of it was due to Rassilon's thoughts echoing through the Master's head. Either way, it was very real to the Master.
He wanted to explain his plan, but words were getting harder to find. He was thinking in broad concepts now. "You wanted my regenerations. You tried to take them. Mine. Yours. Everything locked away. Apart." He gritted his teeth as fire burned through him. The Master tried to pull away, but he held on tighter.
"You've waited too long," the Master whispered, wide-eyed in fear. "It's too much, it's going to tear you apart completely--"
"Not too much. Just enough. I hope." He took a deep breath, and found more words. "You've never...let me help you. Not asking this time. We go together."
"You're going to kill us both." There were tears in the Master's eyes.
The Doctor swallowed back his own tears. "I'm going to save us both." He gripped the back of the Master's neck, pulled him into as tight an embrace as he could manage. "Trust me. Please. Just this once."
He reached out with his mind, expecting resistance, but the Master's shields were as burnt out as the rest of him. Their minds flowed together suddenly, and there was anger and fear and resolve and hatred and love and confusion and regret, and there was no sorting out whose emotions were whose. And then there was burning and fire and ending and pain and death, and one of them raged defiance at it and one of them wept, in terror or sorrow or welcome.
And then there was light.