Disclaimer: I don't own Doctor Who, Babylon 5, or either of these two fantastic characters.

While There's Life

"My whole life has been leading to this."

Commander Sinclair turned the letter over in his hands. It was nearly time. Time for an ending – and a new beginning. The chrysalis was nearly ready. Zathras was busy making some preparations for their return to normal space. Only one thing remained.

Slowly, Sinclair rose and approached the chrysalis. He was still a few paces away, however, when he was interrupted by a noise – a loud, wheezing, whooshing noise coming from behind him. Sinclair turned in time to see a box – a small, blue box – appear out of thin air.

Sinclair took a step back and assumed a defensive pose, but his gut told him this wasn't a threat. He waited a moment, then took a few cautious steps forward. Nothing. Closer. He took one last step towards the door and knocked softly. "Hello?"

Noises. Footsteps, shuffling and slow. The door opened a crack, then farther, revealing an older man, tall and curly-haired and on the verge of collapse. The stranger staggered forward a step, but his legs gave way beneath him. Sinclair reached out instinctively and lowered him to the floor as gently as he could. "Zathras!" he called, hoping his companion was close enough to hear. "We need help in here!"

"No." The stranger's voice was weak and tired. "No, it's all right; don't trouble your friend. There's nothing … nothing you can do for me. I just need to rest … just for a moment."

Clearly, he needed more than that. "What happened?"

The stranger sat up a little. "A giant spider and I had a bit of a disagreement over a blue crystal that ended with a rather nasty dose of radiation. I'm dying; there's nothing to be done. I just wanted to get back home before…" He shook his head. "But there was an explosion as I took off, and the Tardis lost her bearings. When I saw your ship traveling through the vortex, I thought…"

"You could use it as an anchor – wait here until your ship works out how to get you home," Sinclair finished.

"Yes. It shouldn't take long. She's a smart old girl, even if she's a bit stubborn at times." He smiled fondly, but the smile quickly gave way to pain as he sank back to the floor.

Sinclair reached for a nearby pillow and slid it beneath the stranger's head. "Thank you," the stranger whispered, trying his best to smile.

"Is there anything I can do?" Sinclair asked.

"Just … just help me stay awake. If I lose consciousness, I don't know if…"

Sinclair nodded. "All right." He hesitated, unsure. "What's your name?"

"Good place to start," the stranger agreed. "I'm the Doctor. And you?"

"Commander Jeffrey Sinclair."

"Commander," the Doctor repeated, amused. "Surrounded by the military to the end. Well, I suppose there's something to be said for symmetry. What brings you to the time vortex, Commander?"

"A war. A very old war."

The Doctor smiled wryly. "I might have guessed. A crucial battle? Fate of the galaxy at stake?"

"The galaxy? I suppose so. If I fail, the future changes. I caught a brief glimpse of that future, Doctor – a future in which our enemies came back stronger, sooner. My closest friends, all gone. If I can save them … I know it's about more than that, but … that's what makes it worth it."

The Doctor nodded thoughtfully. "Because it's a one-way trip, isn't it. This ship – it wasn't designed for time travel. Wherever you're going, you're not coming back."

Sinclair nodded. "Yes. A new beginning. A new life. A new … well, a new me. You see, where I'm going – this war – humans aren't involved. It's too far in our history – much too far. And the Minbari … if they found a human on board this station, that would change everything. So I have to become one of them."

The Doctor smiled. "Ah, so that's what that is." He nodded towards the chrysalis. "I was trying to place it, but it's been a while since I've seen one, and my memory's a bit cloudy at the moment, I'm afraid." He closed his eyes, catching his breath. "Don't worry, Commander," he said at last, quietly. "It's nothing to be afraid of."

"Have you—"

"No," the Doctor chuckled softly. "No, but I know a thing or two about … dramatic changes. Have a bit of experience myself, in fact. May happen again – I'm honestly not sure. It hasn't started yet, and I don't know how much longer…" He trailed off for a moment.

"Doctor?" Sinclair shook his shoulder gently. "Doctor, you have to stay awake. Stay with me – just a little longer."

"I … I'm trying." The Doctor's eyes fluttered open.

"What hasn't started yet?"

The Doctor laid a hand on Sinclair's arm. "It doesn't matter. Just remember … when you change … the most important part of you will still be there. You will still be you, and you—" he smiled faintly, "—are exactly what they need."

Sinclair shook his head. "You don't even know me."

"I know enough. When my ship appeared, you didn't shoot. You didn't try to blast the doors open. You didn't even sound an alarm. You knocked. When I asked you about the war, you didn't even bother to tell me who you were fighting; you told me who you were protecting. And despite the urgency of your mission, you took the time to … to offer a little comfort to a dying stranger. You may be on your way to a war, but, at heart, you're a man of peace. And they'll need that."

Sinclair stared for a moment, at a loss for words. At last, he took the Doctor's hand and gave it a gentle squeeze. "Thank you. I needed to hear that."

The Doctor smiled weakly. "You're most welcome, Commander."

"Valen," Sinclair said quietly, and the name sounded good. "It's 'Valen' now."

Even as he said it, there was a gentle humming noise. "Well, Valen," the Doctor smiled. "It seems the Tardis is ready. Would you…?"

"Of course." Sinclair gently helped the Doctor to his feet and half-carried him to his ship. "I hope you make it home." Probably not quite right, but he wasn't sure what else to say.

The Doctor nodded. "You, too. I know it won't seem like 'home' at first, but you'll be surprised how … how quickly you'll grow fond of it." He smiled. "Goodbye, Valen, and good luck." He stumbled through the door and closed it behind him.

Sinclair watched as the blue box disappeared. "Goodbye, Doctor," he said quietly.

Sinclair turned back to the chrysalis. It was time. He smiled, an odd sense of peace coursing through his whole being. Holding onto that, he stepped inside, and the change began.