Chapter Text
Author's Note. By the gods, I've returned! And I bring with me more Doom!Trek fanfics. This particular one has been sitting a couple years, and I finally managed to find the time and inspiration to actually do some extensive work on it. It's a bit of a different take, on the character of John Grimm. It's generally been established he's essentially immortal and immune to nearly everything. But...what if he really wasn't? It's a vast universe out there after all. I do hope you all enjoy yet another angsty fic from me. I do so enjoy writing this type of thing. Poor John.
Another day, another mission.
Starfleet sure knew how to pick them.
Offhandedly, Leonard was wondering why he was trudging through a sweltering jungle on an uninhabited planet behind one blonde-haired Captain and a pointy-eared First Officer.
Oh, that’s right.
He’d volunteered. Unwittingly.
Leave it to Captain James insufferable Kirk to want to bend regulations just so he could get some fresh air on a planet-side survey mission. Spock was one thing, being a science officer and all, it was part of his job. But Jim? No. The little shit wanted to stretch his legs. In a jungle. Full of all sorts of flora, fauna, and potential disease.
He had informed the brat of that very fact. That someone with his never-ending list of allergies would be better off leaving it to one of the less danger-prone crew members. Did Jim listen?
Of course not.
‘You should come with us, Bones! That way you can be right on top of things if something goes wrong.’
On top of things. Yeah. Uh-huh.
So here he was, with his clothes stuck to him like an extra skin, making him feel like he hadn’t washed in weeks. It felt disgusting. Leonard scowled.
“I can hear your grumpiness all the way up here, Bones!” Jim called over his shoulder.
“Damn brat,” he grumbled.
Jim must have heard him, flashing a crooked grin before continuing to lead them through the foliage along what appeared to be a frequently used animal trail. “Hey, this looks interesting!” He pointed at a glowing red beetle roughly the size of his fist perched on a rotten log. Pulling out his tricorder, he attempted to scan the insect, but, startled by the shadow that suddenly loomed over it, it uttered a peculiar squeak and scuttled away into the dense underbrush. “Huh?” Jim leaned over the bushes, trying to relocate it. “Come back!”
“Captain, I fail to see how the creature would understand any orders you may give it,” Spock remarked idly.
Jim shot his first officer a dirty look. “I know that!” He stepped back, disappointed. “Well, maybe we’ll find another.”
They did, further down the path. Spock managed to scan the insect, noting its mildly radioactive properties, but once again it eluded them when they attempted to collect it in a jar.
The deeper they pushed into the jungle, the denser the growth became, vines hanging in thick curtains from towering trees that blocked out much of the light above. The air grew heavier, thick with humidity and the scent of overripe vegetation.
“Captain,” Spock began, scanning the surrounding foliage with measured interest, “I am detecting a significant concentration of botanical energy signatures approximately twelve meters ahead.”
“Botanical energy signatures?” Jim perked up immediately. “That sounds promising.”
“That sounds like trouble,” Leonard muttered.
They stepped into a small clearing, if it could be called that. At its center stood a plant unlike anything Leonard had ever seen: a massive stalk rising nearly seven feet high, crowned with a swollen, iridescent bulb the size of a beach ball. Its surface pulsed faintly beneath translucent veining, vibrant hues of crimson, gold, and electric blue shifting beneath its skin like something alive.
“Well,” Jim breathed. “That’s not creepy at all.”
“It is quite remarkable,” Spock said, circling cautiously. “The pigmentation suggests active metabolic processes even in its dormant state.”
“Dormant?” Leonard eyed the thing skeptically. “That doesn’t look dormant.”
Spock stepped closer, tricorder humming softly. “The gametophyte sac appears pressurized. I would advise—”
There was a sharp crack.
He moved without thinking. Lunging forward, Leonard shoved Spock hard in the chest, knocking the Vulcan backward just as the bulb ruptured. The swollen head of the plant exploded in a violent burst, engulfing Leonard in a dense cloud of bright orange pollen. Heat seared through his sinuses and down his throat. He doubled over instantly, consumed by a violent coughing fit that tore painfully at his lungs.
“Bones!”
He barely registered Jim’s voice over the ringing in his ears. His eyes flooded uncontrollably, vision blurring into streaks of green and yellow. He sneezed once, sharply. Then again. Then a third time, each one snapping his head forward and rattling his skull. He waved a hand blindly through the air, both to disperse the acrid particles and to keep the others back.
“Stay back,” he rasped between coughs, sucking in a breath that only burned worse than the last.
Spock was already scanning him. “Doctor McCoy’s vitals remain within normal parameters.”
Normal.
Leonard wiped at his streaming eyes with his sleeve, blinking rapidly. His nose burned, his throat itched, and his skin prickled faintly where the pollen had settled. He sneezed again and straightened stubbornly, forcing himself upright despite the lingering irritation.
“Perhaps you should return to the Enterprise and have Doctor M’Benga examine you further,” Spock suggested.
“I’m fine,” Leonard insisted, voice rough but firm. He scrubbed at his face again and took a steadying breath. “It’s just a respiratory irritant.” Another sneeze caught him off guard. He glared at the now-deflated plant as if it had personally offended him. “With my luck,” he muttered, “it’s the alien equivalent of ragweed.”
Jim folded his arms. “You don’t look fine.”
“I don’t need to look fine,” Leonard shot back, still blinking away tears. “I just need to be fine.”
Spock tilted his head slightly. “You are exhibiting mild inflammatory response and elevated histamine markers.”
“And you’re exhibiting a talent for stating the obvious,” Leonard replied. He rolled his shoulders once, deliberately steadying himself. The coughing had subsided, leaving only a faint rawness in his chest. “Give it a few minutes. My system will clear it.”
It should have already.
He dismissed the stray thought before it could take root.
Jim was still watching him with open skepticism.
“Honestly!” Leonard protested, swiping at his watering eyes one last time.
Spock lowered the tricorder, though his own expression suggested he was far from satisfied. “I would advise caution.”
“You always do,” Leonard replied dryly, stepping past him. “Let’s finish what we came here to do.”
“If you insist, Doctor,” Spock said evenly. “I would cite regulation, but like the Captain, I suspect you would choose to ignore it.”
Leonard shot him an annoyed look over his shoulder. “I’m a doctor, Spock. When I say I’m fine, I’m fine, dammit.”
“So you say, Doctor.” Spock scanned him one more time, but seeing nothing notable, he clipped the device back onto his belt and looked at the now deflated flower hanging pitifully from its stem. “Captain, this species of flora has a peculiar disbursement of gametophytes. Before we proceed, please allow me to collect some specimens to study later.”
“That’s why we’re here, Commander,” Jim waved his hand. “Go for it.”
With careful precision, Spock cut the flower’s head off just below the receptacle and placed it inside one of their sample containers. Eyeing the ground momentarily, he withdrew a small vial and carefully scooped some of the orange powder into it.
“Captain,” the Vulcan began as he straightened, securing the vial, “I recommend we conclude surface operations. The dispersal mechanism of this species suggests additional specimens may be primed to rupture.”
Jim glanced around the clearing. “You think there are more of these things?”
“It would be statistically probable,” Spock replied. “The concentration of botanical signatures remains elevated.”
Leonard dragged in a breath and immediately regretted it. The rawness in his lungs hadn’t faded. It felt deeper now, less like surface irritation and more like something clinging stubbornly to the inside of his chest. He cleared his throat once, then again, but the tightness remained.
Probably just inflammation.
“We’ve already got samples,” Jim said. “No reason to stick around if the local plant life doubles as a grenade.”
Grenade. The word echoed strangely in Leonard’s ears, stretching just a fraction too long. He blinked hard. The jungle seemed louder all of a sudden. Insects droned overhead in a high, constant pitch. Leaves shifted against one another with a dry whisper that sounded almost deliberate.
Spock’s voice continued, calm and measured. “Doctor McCoy’s respiratory rate has increased by twelve percent.”
“I’m standing right here,” Leonard muttered automatically, though even to his own ears his voice sounded distant.
“Then stand there a little steadier,” Jim shot back lightly. “You’re swaying.”
He wasn’t.
Was he?
The clearing felt smaller now, the colors too sharp. Greens were almost fluorescent, and shadows stretched too long across the ground.
“Captain,” Spock spoke quietly, “his pupils are dilating.”
Leonard pressed his fingers briefly to his temple. The pressure helped, if only for a second.
It was just pollen. His metabolism should have neutralized it already.
“Bones?” Jim’s tone shifted, humor thinning. “You good?”
A voice cut through the jungle.
“Still breathing, huh, Reaper?”
Leonard froze.
Spock was still speaking. “Captain, I advise immediate transport—”
But the words blurred together, syllables stretching and distorting as if spoken underwater.
“Thought you’d have dropped by now,” the other voice continued, rough and unmistakably familiar. “Guess they really did make you special.”
No.
His pulse spiked. Slowly, deliberately, he turned his head toward the undergrowth.
Jim was saying something else now. His mouth was moving. Leonard could see it, but the sound didn’t reach him properly.
“You gonna run again?” the voice asked. “Or you gonna finish what you started?”
The foliage shifted, and for a split second, he saw him.
Asher Mahonin.
Standing between the trees.
Uniform torn. Eyes too bright. Smile all wrong.
Leonard staggered back.
“Bones!” Jim’s voice cut sharper this time, closer. Real.
“You left us up there,” the apparition said quietly. “Left us to burn.”
“I didn’t—” Leonard tried, but his tongue felt thick, uncooperative.
“Captain,” Spock said firmly, “he is experiencing acute neurological distress.”
The jungle warped; colors oversaturated and the air shimmered like heat rising off metal plating. The ground tilted beneath his boots.
“You survived,” Asher growled, almost feral. “Funny how that keeps happening.”
Leonard opened his mouth to answer Jim, to say something rational, something grounded, but only a strained, broken sound escaped him. He saw blue rushing toward him.
And then everything went black.
The doctor’s weight pitched forward.
Jim swore and reached out to catch him, but Spock was already moving. The Vulcan stepped in seamlessly, one arm bracing Leonard’s chest while the other secured his shoulders before he could hit the ground. Leonard’s body felt unnaturally hot even through the fabric of his uniform.
“Bones!” Jim dropped to one knee beside them.
Leonard’s head lolled. His skin had gone ashen beneath the streaks of jungle grime, lips parted slightly as his breathing turned shallow and uneven. His eyes fluttered once, unfocused, then rolled back as his legs finally gave way beneath him.
Spock lowered him carefully to the forest floor. “Captain,” he said evenly, though strain threaded beneath the composure, “Doctor McCoy’s core temperature and cardiac rhythm are escalating rapidly. If it continues to rise..."
Jim did not wait for further explanation. He snapped open his communicator. “Kirk to Enterprise. Medical emergency. Three to beam directly to sickbay. Now!”
The jungle dissolved in a shimmer of transporter light, leaves and shadows fragmenting into gold as they vanished from the clearing.