The hospital walls were white and sterile; discomforting in a way that the interior of the medbay had never been. Or any other hospital, for that matter, even though they looked almost identical. Hell, McCoy was sure he'd been in this hospital before and never found it as suffocating as he was finding it now.

Deep down, he knew it wasn't the walls that unnerved him. He couldn't quite admit it to himself yet, though; that would mean acknowledging the real reason his skin itched as though it didn't belong to him; behind the fuzziness in his mind that hinted at the possibility that this was all just a terrible, terrible dream.

He wished it were a dream. He would give anything – his soul, the world, the universe, anything – to be able to wake up from this, wander onto the bridge and see his captain sitting in his chair in that infuriatingly cocky manner of his.

But he knew that wasn't an option. It was one of those universal certainties that he could feel in his bones, in the same way he knew that there was no god, that Spock had emotions, that Jim was dead.

He could still picture those blue eyes dancing with emotion, with life, as they had been the last time McCoy had seen them open. "Just a routine mission, Bones," Jim had said. The wanker. "Nothing to worry about. I'll be back before you know it."

He'd been wrong on all counts. It'd been three days and when Jim had returned he'd been hovering on the brink of death with alien venom surging through his system. And McCoy hadn't been able to do a damned thing. He'd been absolutely helpless to do anything but watch and mentally urge the ship onwards as they'd zoomed towards the nearest Starbase as fast as the Enterprise could go.

He thought they'd got there just in time. Jim was still breathing as they beamed him down – just, but he was breathing.

He didn't stay breathing, though.

McCoy had watched helplessly as they'd injected him with the anti-venom and attempted to restart his heart. And he'd watched Jim as the doctors pressed down on his chest, willing him to take that gasp of air that he knew was coming.

But it never did.

So here he was, wandering the halls of the hospital where Jim had died. Still hoping against hope that he'd wake up.

Almost without consciously deciding to, his body made a detour off the beaten track, swerving sideways towards the closed door of a private room. He knew it was empty; there was no name on the door, and all the rooms in this ward were for long-term patients.

He wasn't sure why he entered the room. Perhaps it was because he was aware he was walking around as though in a trance, and on some level the pitying and curious looks he was receiving did bother him. Perhaps he just wanted somewhere to be alone.

Or perhaps there was a part of him that knew that this was where Spock would be. That some subconscious part of his mind knew that he was needed here, and that he needed to be here.

The figure in front of him was facing the opposite direction but McCoy didn't need to look twice to know who it was. Even without the pointy ears, slightly-green skin and blue shirt, McCoy would have recognised him from his stiff posture alone. But there was something wrong with how he stood… something different.

It took him a moment to realise that Spock's shoulders were trembling slightly. Almost unnoticeable… but it was there.

"Spock?" McCoy said. He hadn't meant for his voice to come out that soft or gentle. His nature was gruff, and he didn't do this sort of shit. Not before, and certainly not now. Not when he'd just lost his… everything.

Because there was no other word that quite summarised what Jim Kirk was to him. Best friend? Yes. Unrequited love? Yes. Man-who-he-threatened-to-strangle-at-least-once-a- week? Definitely.

But Jim was so much more to him than anything he could ever name. Jim was his universe; the man who'd convinced him without saying a damned word to venture out into space despite the fact he was fucking terrified of it. Despite the fact he was such a good surgeon and could have had his pick from postings on Earth, he'd followed that blonde-haired, blue-eyed little fuck into the darkness, and had never looked back. McCoy had let Jim fix him, let him drain the worst of the temper and the cynicism from his thoughts and let Jim remind him that just because his life had taken an unexpected turn didn't mean that it was over.

He'd convinced McCoy to live again.

"Doctor McCoy," Spock said, without turning around. McCoy frowned; Spock was behaving very peculiarly. "Was there something you required?"

No, McCoy thought. The only thing I require is gone. But he didn't say that, partly because he felt it would have sounded pathetic, and partly because the day he talked about his feelings with a Vulcan was the day he volunteered to be put in a mental institution.

He realised he didn't have anything he could tell Spock. He hadn't spoken to anyone since Jim… well, for a few hours, anyway. He didn't know what was happening with the Enterprise, or with her crew, or… Oh god, he realised. We need a new captain. Spock's almost definitely going to be the new captain.

"I wanted to see if you were alright," McCoy said, swallowing the lump in his throat. "I realise now that I already know the answer."

Spock turned around, and to McCoy's considerable surprise he saw the tear tracks running down Spock's cheeks. He'd always known that Spock had emotions buried somewhere deep in his cold Vulcan heart, but seeing him grieve this openly was still incredibly unexpected.

"I am not prone to exaggeration or dramatization , Doctor," Spoke said, "Nor do I usually speak in a figurative manner. But I wonder, at this present moment, whether I will ever be alright again."

Well, damn, McCoy thought. Because coming from the stoic Vulcan, that might as well have been a declaration of love.

He had nothing really to say that could comfort Spock in any way, so he simply murmured, "You and me both."

Spock assessed him shrewdly. "You too were very close with the captain," he observed, and McCoy had to risk biting out, Closer than you ever were. Because that would have been his grief talking, and anyway, he suspected it was only partly true. His relationship with Jim had been very different to Jim's relationship with Spock, but that didn't make one greater or lesser than the other.

So instead he simply said, "I loved him."

"Love," Spock said, rolling the words around in his mouth as though it was foreign (which, given his native language was Vulcan, McCoy realised it actually was). "That seems an… apt word."

McCoy wondered how the conversation had strayed into such unexpected territory. He cleared his throat. "I should leave you to you… privacy," he said, making the turn for the door. Before, hating the idea of leaving the company of the one person who could understand what he was going through, he turned back quickly. "At least Jim would be pleased to know his one true love's in such capable hands."

Spock looked confused at this. "I do not follow, Doctor."

"The Enterprise?" McCoy replied. "You're the captain now." It came out as more of a question than he'd intended.

"I'm afraid I am not," Spock responded. "Starfleet have already asked me to take over captaining the Enterprise on a permanent basis. I declined."

"Vultures," McCoy spat. Jim had only been dead a few hours. They should have damn well waited. Then the rest of Spock's statement caught up with him and he did a double take. "Wait, what? What do you mean, you declined?"

"I refused to take the position," Spock said calmly, as if this was an entirely expected piece of news.

"Why?" McCoy was baffled. Captain was the obvious next step for Spock, who was acting-Captain almost more often than Jim was, what with the amount of time he spent on away missions or banged up in McCoy's care after said away missions went wrong.

"I feel I am best served in my position as Science Officer," Spock said. "It is what I enjoy, and I would miss it should I accept the promotion to Captain." He hesitated, then added, "Furthermore, the idea of taking up Jim's old position after his death caused me some emotional consternation, the cause of which I do not fully understand myself."

Which translated from Spock-language to "I would have felt like I was trying to replace the Captain, but I don't know that yet."

"Jim would want to see the Enterprise in the hands of someone he could trust," McCoy told him. "He wouldn't want some pompous captain who'd never set foot on her to come in and take over."

"I enquired as to who they'd offer the captaincy to after I refused," Spock said. "It seems Mr Sulu is the most likely candidate."

"Sulu?" McCoy said. "The boy's barely out of the Academy!"

"He graduated at the same time as Jim," Spock said. "And has had four more years' experience aboard a Starship than Jim had when he was made Captain."

McCoy paused at that. It was sometimes very easy to forget that Jim had been given a Starship before he'd even graduated. And Sulu… well, he wasn't who McCoy would have picked, but he certainly expected him to become a captain eventually.

Just not so soon.

He'll make a good captain, McCoy realised. He'd seen Sulu in action when Kirk and Spock both went on away missions, and he rarely put a foot wrong. There was a difference in taking charge temporarily and being Captain on a permanent basis… but the same could be said had Spock taken over. Spock was a good captain in a crisis, but for a lot of that he'd had Jim to balance out his logical way of doing things.

"I do not think you need to fear for your position, Doctor," Spock said. "I believe you will remain Chief Medical Officer regardless of who receives command."

It took McCoy a moment to comprehend what Spock was talking about, but when he did he felt like punching him. "I don't care about my position, you damned hobgoblin! I couldn't care less about my job right now!"

Spock looked at him appraisingly. "My apologies, Doctor McCoy," he said. "I did not intend for my remark to be offensive."

For a few moments, McCoy considered punching him anyway, reasoning that at least it might make him feel better. But then, without warning, the anger drained from his body and his shoulders slumped exhaustedly. God, he was tired. He wanted to crawl into bed and forget everything that had happened these past few days. And maybe when he woke up, he'd find that it hadn't happened at all.

"Apology accepted, Spock," he said. "If I'm honest, I'm not even sure I'll be returning to the Enterprise."

Spock raised one eyebrow in surprise. "But it is where you're stationed, Doctor."

"Yeah, well." He ran his hand tiredly through his hair. "I had ground offers, you know, when I first graduated. It's what I wanted; the reason why I joined Starfleet was because they assured me there were plenty of medical vacancies on Earth, and that with my qualifications I should be able to get one. I hate space. I hate flying. I had teleporting. I hate the danger and the darkness and aloneness of it all. But then Jim got the captaincy, and amongst the many earthbound job offers I got was a single letter requesting I be CMO on the Enterprise."

"And you took it," Spock said.

"And I took it."

There was silence for a while.

"I built my life around him, you know," McCoy said. "From the moment we first met. At first it was like I couldn't get rid of him. He followed me home and hacked into the timetabling system so we had most of our classes together. He just wouldn't piss off. It took me a few weeks to realise that I didn't really want him to."

He couldn't believe he was telling this to Spock, of all people. The emotionless Vulcan who'd sooner chop of his own arm than admit to engaging in human behaviour. But then he glanced up and saw the tear tracks that still marked the other man's cheeks, and realised that perhaps this was exactly who he should be telling this to.

"He wormed his way in there, you know," McCoy said. "And made this giant hole that only he could fill. But he did fill it, so it was fine. And now he's gone." His voice broke on the last word, and to his shame he realised he was crying.

Doctor McCoy jumped when he felt a hand clasp his shoulder and almost took a swing at Spock, thinking he was about to perform the Vulcan nerve pinch. But then he looked up, and saw that Spock had started crying again too. It was supposed to be an expression of sympathy.

"I grieve with thee," Spock said quietly. And McCoy nodded, because he realised that Spock really, genuinely did.

They stood like that for a while longer, grieving together.