"Do you really have to do this?" Clark's voice was thick with uncertainty. He was facing away, absently flicking buttons on Bruce's computer. The Batcave was swamped by the distinctive smell of rotten flesh.

"It's a dead body, Clark. Decaying flesh. Don't start forming emotional attachments with a slab of expired meat." Bruce whirled the table around in the Batcave and pulled out a set of surgical instruments. "And if you don't want to recycle your lunch, I suggest that you keep your eyes on the screen."

Bruce worked silently, occasionally noting a discovery that he wanted Clark to input into his computer. The generalizations were easier to manage. Bruce was inspecting first by observation, without cutting through skin and flesh. Clark tried his best to think of Alfred's sandwiches. Delicious club sandwiches. Chips on the side.

"Contact with Kryptonite works like radiation exposure." Bruce frowned, trying to discern clues from the unrecognizable mound of flesh. The low underground temperature and airtight coffin had slowed the decay tremendously. "Overexposure to Kryptonite stimulates a mutation akin to acute myeloid leukemia. Complete with petechiae on arms and legs."

Bruce looked up briefly. "Are you typing that down?"

Clark was hugging himself at the console, keeping his eyes resolutely on the keyboard. "Yeah." He reached out and did what he was told, despite the intense shaking of his fingers.

"Organ failure. Let's see where that begins."

Sounds of metal cutting flesh was quickly driving the sanity out of Clark's weakened mind. He numbly followed the systematic sounds of moving scissors. Sandwiches. Chips. Sandwiches. Chips.

"You never told me what you do for a living now." Bruce spoke to him in the manner of an afternoon tea conversation.

Clark grasped at the question like a lifesaver amidst the disturbing background noises. "Gotham Gazette. I used to work there. Not since… six months ago. I couldn't." He breathed, wanting to sigh, then he vowed never to breathe again. The thick pungence attacked his nostrils like nothing else. "When I get better, I'll reapply."

"If you need a degree for a new civilian identity, I can buy that for you." Bruce offered. "I'd prefer Princeton, but if Kansas State is what you want…" He shrugged carelessly. "Any university, any degree."

"I'm good. I just need to work my way up." Clark managed a small smile. Hearing Bruce's voice in normal conversation was comforting. "I never thought I'd give up writing one day. It was my favorite pastime."

"I remember."

"Back then, I could never imagine leaving the Daily Planet..." Clark imagined the pen in his hand, compared to the electronic tablet that he now carried around. "But I had no choice. I was too young, among people who were growing old too fast. Lois was understanding when I left."

"Hm."

"Bruce."

"... Hm?"

"Do you think..." Clark willed himself to look in Bruce's direction. He ignored the unrecognizable mass of flesh on the table. Bruce's gloves were stained with color. "Do you think you'd be able to save yourself?"

Bruce looked up briefly, studying him with narrowed eyes. "That is a very odd way of phrasing your question."

"I mean…"

Bruce cut him off with a knowing glare. "Who knows? Thirty years might just be enough to invent a cure for Kryptonite-induced cancer."

"You know you can't change the past, right?" Clark said quietly. "No one can."

"I can change the future." Bruce glared back steadily. "Your past and present are my future."

"What you did in your future and my past are the same. You never found a cure. You tried."

"How encouraging."

"The universe self-corrects, Bruce. You will never find a cure. Or you will find a cure but not the necessary ingredients, or your drug will not work, period. The universe will do anything in its power to stop you from getting your way."

Bruce shrugged, dismissing the long-winded explanation that Clark had thrown his way. A part of him understood why Clark was so desperate. Clark was denying himself false hope. Willing away all the unlikely possibilities, to save himself the disappointment. Just so he wouldn't be lifted into the air only to crash back down again.

"Kansas State must have upped their quantum physics courses." Bruce commented offhandedly.

"I cover the science section of Gotham Gazette sometimes."

"You think I lied then."

Clark's head jerked up at the accusation. "About what?"

Bruce didn't spare him a glance. He was concentrating on separating the mingled rotten tissues. "When I first got here, I said I needed to get back so Bruce Wayne from thirty years ago would wake from his coma. You think that's a lie."

"I think…" Clark swallowed slowly. "That's not how the universe works. What happened has happened. In my memory, you woke. Whatever you do now, the universe will guide you to waking thirty years ago. The difference is, it's not that you need to go back… You want to go back."

"I want to go back because I want to save my life." Not because I don't want to spend time here, with you.

"I know." Clark nodded wearily in understanding. "I'm telling you you can't. You died in my past. In my arms." So stay for as long as you can, with me. Don't waste away your hours finding a cure that will never succeed.

Bruce yanked something out of the corpse with more force than necessary. Something hardened over time tangled with something darkened with oxidation. Clark turned away gingerly. "I'll fight the universe." Bruce said nonchalantly.

"You can't just-" Clark stopped mid-sentence and sat down defeatedly on a bench.

"You don't know that."

"The universe-"

"What if this isn't about the universe?" Bruce countered defiantly. Clark looked up, confused. "What if this is no more than a premonition? A warning my brain has computed based on probabilities of the future during my coma? Then there is nothing stopping me from shaping the future. Because what I am seeing is what my brain predicts to be the future, and not the future itself."

Sure, that is a possibility. From Bruce's perspective, there is a fifty-fifty chance that is true. He has no way of knowing whether he is experiencing reality, or just a fancy, video-game-like coma. Clark bit his lip nervously. For their encounter to be a dream, it was an optimistic outlook at their situation. A very improbable possibility. Clark had his own mind, his own history. He certainly didn't feel like he was an image existing in Bruce's subconsciousness. "But... what if this is coma-induced time travel?"

Time travel was what they had always agreed on, since discovering Bruce's machine and his blueprints. It was still the most logical explanation.

Bruce's hands stilled momentarily. He looked straight into Clark's eyes. "Then this is all the time we have, and I will never see you again."

"I… I don't understand."

"By law of Novikov's self-consistency theory, the universe self-corrects. I will never find a cure." Bruce explained irritably. "That is the pessimistic possibility that you insist on. You believe in the universe."

"And I believe in the multiverse." Bruce continued. "If I find a cure, I'll spend my successful reality with a different Clark Kent. Even if I can't, I've tried, and that attempt is based on my knowledge from the future. Which means my perception of reality will branch off to an alternate universe. My failed reality will also be spent with another Clark Kent."

Something clicked in Clark's mind. Something that he understood, but was unwilling to acknowledge.

"Yes, Clark. I can still save myself. If I succeed, I have a new future waiting for me." Bruce's voice echoed in the Batcave, driving the answer deep into Clark's empty core. "But I can't save you. Whether I succeed or not, the Clark Kent waiting in my future will not be you. When I leave, you will never see me again."

For the longest silence, Clark felt time ticking past in the tormenting detail of a working clock. Then Bruce was done, pulling off his gloves and walking past him. On his desktop were labelled petri dishes and small glass containers, everything that he was going to study and overcome. His attire still smelled of rotten flesh. Reminding Clark of a certain death. A death he could never rewind.

"I'm Batman. I never claimed to be anyone's savior." Bruce discarded the gloves into the bin and walked away, leaving Clark alone in the vast space of the Batcave with his lifeless corpse.