"He's a murderer!"

"But so are you!"

River closed the door behind her softly and rested on the ramp. The Doctor stomped past her and slammed down controls on the console. He jammed levers downward and yanked on plotters, forcing up switches. The sound of his feet clanking on the grates ceased half way around. Obscured by the time rotor, he smashed his hands down. River took it like a blow. She felt guilt, like blood, pulse through her veins.

"How dare you," he hissed at last, not moving. River closed her eyes. It left his throat again in a cry. "How dare you!" He emerged from behind the console. "I did what I had to do! What right do you have?"

"My love, I—" What was she supposed to say? How to explain that she'd only been trying to keep them safe, trying to get the gun out of his hand, and the words had just come out? Murderer. So easy to say. Was that because it was true? "I'm sorry," she finished weakly.

"No. No! You don't get to apologize. Because I faced it, not you. I fought on the front lines when I could have kept running. I watched them all die, over and over and over, at the hands of the most terrible beings history has ever devised. The Nightmare Child. The Could-Have-Been King. The Neverweres. And if you think, if you think for one second that I wanted to kill them... my people…" he shook in a breath and swallowed the tears in his eyes. "Then you're wrong."

River stayed silent as he paced the round of the TARDIS. She stared at his back and leaned against one of the coral beams. She missed the familiar gait of her Doctor, all tweed and hair, bowtie and confidence. And in the end she would lose him too, give him up to this agony. Their futures lead to the wrong places. She wanted to go home and feel his easy smile remember her. Homesick. That was new.

"But the man I know would never pick up a gun like that," she replied at last. "He wouldn't threaten someone, he wouldn't intend to shoot them, no matter what good it did the world, and out there, today? That wasn't you. You would never. And if you weren't going to listen to me, I had to say something to—"

"Something?" he yelled. "Comparing me to that… that man," he pointed out the TARDIS, arm quivering. "Is that your strategy? You? Is that my future, River Song?" A smile cut his face, cruel and demeaning. "Because I don't want it!" His voice collapsed just before his knees, and he caught himself on a piece of coral, trying to hide it. His age crawled over his face, and suddenly, River could see the toll of each and every one of those nine hundred years carved in his eyes. She knew what he wanted, the irredeemable ache of a thousand genocides on his hearts. Life after so much death.

"Doctor…"

"But in the end, I suppose you're right." Mourning and resignation inched into his posture, beating him down, an old, weary man. "I tried to save them. I tried to save everyone. And I couldn't, it's just I…. I couldn't. They were suffering and they were going to destroy everything, the whole universe. It would've gone on forever, River. The Time War, the last and greatest, without an end.

"And so I had to do it." He looked River fiercely in the eye. "I would've died with them. Should have…." he paused, and quietly, "…I wanted to." The words hung on the air, unrequited. "Now I'm all alone, in the entire universe, and I can feel it. I'm alone."

River took a deep breath and answered decisively, "You've got me." And you will always have me. The Doctor broke the gaze and shifted on the balls of his feet. "So you wanted to save the President because…."

"I've got nothing else left." He shook his head and blinked. Nothing left. River's mouth twisted, but she had nothing left to say. He closed his eyes, waiting for composure; he changed the subject without skipping a beat. "What are you doing here anyway?"

River exhaled, forcing back tears if her own. She tried to smile, but it came off broken. "Trying to keep you from ramming into a time lock, remember?"

The Doctor huffed, sniffing half a bitter laugh. His head shot up, a sudden realization in his eyes. "Wait. A time lock. River, that's….fantastic." He spun and ran back to the console. River bounded up the ramp.

"What?"

"We can do it. We can save the universe." He looked at her and flashed a relieved grin, all pain hidden behind glinting eyes. "And you're going to ask how. But wait a second." River shut her mouth as the Doctor jammed down some buttons and pulled around the monitor. He turned to face her, leaning forward. "A time lock is a huge temporal phenomenon, it takes a ridiculous amount of power, so when it forms it takes time to stabilize. Now, if we collide with it, hurl the TARDIS against it—"

"Are you trying to get us both killed?" she gaped. "That's the craziest plan I've ever heard."

"How long have you known me, again?" He raised his eyebrows.

"Do you understand the kind of surplus energy that it'll take to rip away one timeline and replace it with the proper one? It'll fry the TARDIS to a crisp!"

"Exactly." The Doctor pointed to a lever and River pulled it down and sideways. "The power of the time lock will split the paradox from reality, and we channel it through the TARDIS and into the matrix on Gallifrey. That'll hold it."

"It'll have to be the perfect collision." River followed the Doctor around the console.

"Oh, River Song. Better than perfect." His fingers moved like lightning, coordinates entered into the computer. "Gallifrey technically isn't there anymore, but," his voice dropped off for a fraction of a second, but like it was just any other planet, he kept on, "we can get close. The fringe of the Time War. It'll be bumpy. Old girl won't like it." He patted the time rotor without stopping the flood of characters onto the monitor. "But she can cope. Are you ready?" His hand gripped the last lever.

"This'll mean it's over. You and me. I'll never see you again." River bit her lip. Maybe it was time to let him go. In the end, she knew that this had to pass.

"You won't even remember." He tilted his head and looked at her plainly. "If we do this, then I've got the future, and you'll have the past. Don't you want that?"

River inhaled through her nose. He was right, of course, and she'd seen this day coming for a long, long time. "You stupid man. If you die, I swear I will have your head." The Doctor smiled. It was that big toothy grin, full of mayhem and scheming. River laughed, exasperated, drained. She laid her hand on top of his. They pulled down together.