13: Immortality

Bill had never desired to see her bed more. Her arms ached, her legs felt like noodles, and the only thing keeping her eyes open and her feet gliding ceaselessly across the dirt field below her was adrenaline and the sight of the TARDIS, blue as can be, slowly growing in front of her. The Doctor was running just a step ahead of her, in his peculiar way. As a bright green flash whizzed just behind him between them, narrowly missing the tails of his coat, Bill found some renewed energy.

They'd been running on this barren planet for what felt like an hour now. She couldn't even remember who they were running from at this point. A battle had broken out before the Doctor had planned and suddenly they had found themselves in this field surrounded on all sides by soldiers. From the left came blue sparks, from the right green laser lines. All the Doctor had said was that she better avoid getting hit by either. This was one statement she didn't dare question her tutor on.

The Doctor glanced to his left, then to the TARDIS, then did a double take. Bill noticed his expression drop as he slowed and moved to her left side, giving up his lead and running just beside her. "They're getting closer," she heard him grunt in between breaths. "Just keep running."

Bill pushed onward, feeling her lungs about to burst. Out of the corner of her eye, the Doctor was shifting his gaze to the left every other step. Just as Bill went to grab her TARDIS key from around her neck, the Doctor suddenly called out her name and practically screamed, "Duck!"

Before she knew what was happening, Bill was dropping onto the ground, rolling toward the TARDIS in a heap. The Doctor soon followed, crashing into her just as she tried to right herself. Finally, she untangled herself from him and found her feet, pulling out the TARDIS key. The Doctor gave her a bashful grin from the ground below her.

"Did you push me?"

"Sorry about that. Didn't want you getting hit."

Bill unlocked the TARDIS as she shook her head. "Nah, it's fine, just wasn't sure what happened is all."

She pushed open the blue door, watching the battlefield with a sharp grimace one last time before cocking her head towards the ship. "Better hurry in, then."

The Doctor went to stand, but his left leg suddenly buckled beneath him, forcing him to cry out, more in shock than pain. Bill grabbed him before he could fall forward onto the ground, holding his chest with one hand while reaching the other arm around his back to stabilize him. Her face was lined with worry. "You're hurt."

"It's fine," the Doctor brushed it off, but allowed his companion to take half of his weight with a grateful smile as he limped into the TARDIS. "Nothing too bad, I don't think."

Bill helped the Doctor to one of the never used flight chairs before dashing back to shut and lock the TARDIS doors. By the time she was back by his side, he had rolled up the torn leg of his trousers enough to reveal thin blue lines tracing a miniature circuit board on his shin. Bill eyed him curiously. "Are you okay?"

The Doctor nodded, whipping out his Sonic Screwdriver. He whirred it over himself and read the data with a skeptical eye before answering. "Nothing major. Electro-pulse weapon; should've known by the blue sparks. I'll be fine in an hour or two."

Bill sighed in relief and leaned against the console. Awkward silence took over the room as she tapped her fingers restlessly on the metal panels, eyes looking everywhere except her tutor. Silently, she kicked an invisible dust bunny with her sneaker. "Why did you save me?"

She finally looked at the Doctor, who was still examining his leg. "You could've gotten really hurt, or worse."

"Well, yeah, but so could you."

"I'm less breakable than you."

"How?"

He looked up suddenly, eyeing the console. "Can you pass me the medkit and the blue bottle? They're under the console by your leg."

Bill noted the change of topic but spun around and followed his instructions anyway, dropping the kit onto the empty control deck beside him and handing him the bottle of strangely blue ointment. Cautiously, he opened the bottle and dipped a couple fingers inside. With gritted teeth, he slowly moved his fingers toward his leg.

"Don't know if this is gonna hurt or not."

Sucking in a breath, he touched the ointment to his wound. Instantly, he shut his eyes tightly, biting down his gritted teeth harder. "That answers that."

He repeated the action again, taking some of the healing ointment onto his fingers, but this time Bill latched onto his clean hand with her own. The Doctor turned to her sharply, an odd, unreadable expression on his face. She shrugged. "You risked your life for me. It's the least I can do, honestly."

The Doctor blinked dazedly for a moment, muttering, "Probably not my life. Might have risked a regeneration, though."

Bill's mouth fell open. "Wait, what?"

But the Doctor had put more of the ointment on his leg and started grasping her hand more tightly, grimacing with his eyes closed again. At least, Bill thought, the strange electro-pulse thing seemed to be fading a bit as she watched vivid blue lines turn more and more transparent.

Just as the Doctor's grip on her hand started to hurt, he let out a breath and loosened his hold on her. She wiped her sweaty palm on her jeans as he dug into the medkit, pulling out a roll of gauze. With both his messy and clean fingers, he wrapped the bandage around his calf, neatly tying it off. Bill wondered if maybe he really was a proper doctor. She'd never asked.

When all was finished and the gauze and bottle were both put away, the Doctor looked himself over, holding his gooey fingers awkwardly above his clean trousers. Bill fished a few crumpled napkins out of her pocket and held them out for him. "Souvenir from the chip station."

But as the Doctor reached for the napkins, Bill pulled them up back toward herself. "If I hand you these, will you explain what you meant before?"

"About what?"

"Ughh, 'I'm less breakable than you'?

"Ah."

She handed him the napkins and as he wiped down his fingers, he thought of the right words to use. She beat him to it. "Regeneration. Is that like with starfish? Or worms?"

The Doctor grinned as he sat up, putting the foot beneath his injured left gingerly back on the ground. "It's a bit more complicated than that. When I get hurt or sick and can't survive, every cell in my body is able to regenerate. I become, well, a different person, really."

Bill took this all in, the beginnings of a smile twitching her upper lip. "So that's how you've survived this long."

The Doctor eyed her curiously. She clicked her tongue. "Come on, you practically live in a life or death situation."

"Occupational hazard."

"Thought you said you were just passing through?"

"Well, then, it's my job to just pass through."

Bill watched him for a moment as he tested putting pressure on his wounded leg. The grimace on his face afterward told Bill he wasn't going anywhere soon.

"So you've been different people before? What's that like?"

The Doctor grinned at his student. "Always asking the questions no one ever does...It's strange. You wake up and you interact with the world differently. People treat you differently. Sometimes you treat people differently."

Bill bit her lip before she asked her next question. When she worked up the courage to voice it, she hardly spoke above a murmur. "What's it like to have lived so long? I mean, you're practically immortal right?"

A light in his eyes faded, and his face tilted toward the floor. "Immortality is a funny thing. A funny, funny thing...I've met other immortals. My fault they were immortal. I was younger; less experienced. I condemned them."

Bill felt an ache in her chest as she looked at the sad expression on the Doctor's face. She almost regretted asking. But then he did something very strange, even for the Doctor. He smiled-a sad but happy smile-and looked up at her.

"But that's why I travel with humans. Brilliant, ordinary humans. You lot never have enough time. You run from day to day and hardly ever stop because you know you can't. You help me have perspective. You help me see the wonder in the universe even when I'm too old or cynical to see it. Sometimes when you have too much of something, you don't appreciate the beauty of having just a little bit of it."

Bill had tears trying to escape, but she shook her head and smiled instead. "Do you want me to get you anything? Unless your leg's healed."

The Doctor slowly put his weight on his left leg and took a tentative step forward. "I think I'm okay. Might have some aftershocks for another half hour, but the worst of it's over."

He gave Bill a lopsided grin. "Like it never happened."

But Bill knew she wasn't soon going to forget this. Not him saving her nor their conversation afterward. She had known from the very beginning that travelling with him was the most amazing thing she'd ever done. But now she knew that that care and enthusiasm went both ways. That simple fact would keep her smiling for a long time.