"All right, Bones – are you gonna tell me what's going on?"
McCoy looks up from his computer, perusing a readout on a nearby monitor. He shakes his head, sighs. "Which part of 'what's going on' do you want, Jim?"
"Oh, I don't know. Wanna start with why Spock about knocked me over on the way to the bridge and has Uhura hailing the Revere – without so much as asking me, I might add – and only has time to tell me that it's a 'medical emergency' and I should come speak to you?"
"Yeah, I can explain that to you. Come with me."
They leave the CMO's office, moving to a room in Sickbay usually used for isolation cases. There, attached to a dizzying array of machinery, is...
"Holy shit, Bones – Sulu? What's the matter? I thought..."
"That he was on the mend after this last away mission? Yeah. Me too. Turns out, though – just got the blood work back – he picked up some sort of indigenous parasite on-planet. I can only assume that it got into his system through one of the places where he was wounded – it's small enough that it's not readily detectable, and it must have got past my scans when I was trying to get him closed back up again."
McCoy pauses, and they both watch the unconscious man tossing restlessly on the biobed, his face unnaturally pale except for the spots of high color in his cheeks.
"Parasite, Bones? What's it doing to him?"
"It's a systemic infection, basically. Fever's gotten as high as 42.2 – and even now, I've only managed to drop it down to 41.8. He's experiencing febrile seizures – and you almost never see those in adults, but so far he's had three. Three, Jim – and though they're not dangerous themselves, they look agonizing for him, poor bastard. I've got him on an antibiotic that ought to be knocking out the infection, and we've tried all the antipyretics we can think of to get the temp down. This – he gestures to the machinery – is my last resort; I've hooked him up to dialysis, and I'm literally cooling off his blood supply to try to bring down his body temperature. Otherwise..."
"Could he..."
"Die? Yeah. Very easily." Bones' expression is grim. There could be some serious damage, even if he doesn't – human body tissue just isn't meant to tolerate that kind of fever."
Kirk moves closer to the biobed, and lays a tentative hand on Sulu's forehead. He yanks it away almost immediately.
"Christ, Bones!" He turns from Sulu to face the doctor. "But you haven't told me what this has to do with Spock hailing the Revere – what's up with that?"
"It's like this, Jim. Sulu's delirious – as you can easily imagine – and he seems to have gotten fixated on the idea that he's still trapped somewhere with Chekov. In his head – wherever he is in there – Chekov has died, and Sulu won't leave him. Spock tried to initiate a partial meld with him to bring him back to reality, but he only managed a few seconds before Sulu threw him out."
"He... wait. Threw him out?" Jim's blue eyes are wide. "Threw Spock out?"
"Yeah." McCoy reaches down to feel Sulu's forehead, absently stroking back Hikaru's thick, dark hair as he answers. "If we can get him through this and he gets better, that part'll be pretty funny – don't think anybody's ever been able to do that to Spock before."
He focuses his attention on Jim again. "Problem is, he's given up – almost seems like he's willing himself to shut down. In the time he was in there in his thoughts with him, Spock got the idea that Sulu's made up his mind just to die with Chekov."
"But... Chekov's not dead. Chekov's on the – oh."
Of course. Chekov's been on the Revere for the past three days, helping them with some of their stellar cartography software.
"Spock's getting Chekov, right?"
"Got it in one, Jim. Somebody's gotta convince him to fight – and he'll fight for the kid, even if he won't do it for himself." McCoy shakes his head. "Crazy bastard."
Jim's expression softens as he looks up at the doctor. "Not so crazy. If it was you in that spot, you wouldn't leave me, and you know it."
Bones is silent for a long time. "No. You're right; I wouldn't. And you wouldn't leave me, either." He scans the machines monitoring Sulu's status before serious hazel eyes meet intense blue ones. "Space is no place to be without your best friend."
The doctor's communicator chirps. "Spock to McCoy."
"McCoy here – Spock, were you able to reach the Rev-"
"Hikaru! Where's Hikaru?"
McCoy's question is answered as he's nearly knocked over by the young Russian sprinting into Sickbay.