Kirk was running for his life, legs burning, chest heaving, feet squishing several centimeters into soggy swamp ground as he raced away from the monster that chased him. Beside him ran Spock, who seemed to faring better than Kirk, despite the lacerations to his back and shoulders. The gravity on this planet was more similar to Vulcan's than to Earth's, and Kirk was definitely feeling the effects. His calves screamed under the force of exertion, and his fingers felt oddly cold from lack of blood flow.
Behind them, the monster roared. It was a gigantic reptilian beast native to the swamps and tropical rivers of this planet, a ferociously territorial animal that also happened to be caring for a clutch of eggs. Too bad for Kirk that he hadn't seen the nest until he fell into it, crushing half the eggs. Whoops.
The creature had returned to her nest before the two men could scramble away. Kirk had attempted to stun it with his phaser; however, the blast simply rebounded off of its thick scales, allowing the creature the opportunity to lash out at Spock with its great, taloned paws. Kirk had grabbed Spock's arm and hauled him away, and they took off running in a direction they hoped would lead to the landing site.
So far, no luck, and both men were rapidly beginning to tire. Being physically smaller than the large reptile gave them an advantage, allowing them to dodge through the close-growing swamp trees, but now exhaustion was making then slow and clumsy. Kirk's foot caught on a thick root, and he fell sprawling over the muddy ground. Spock skidded to a stop just as the creature wrenched its way between two trees and stood menacingly over the captain.
Kirk flipped onto his back, trying to keep the monster in sight while ignoring the stabbing pains that were shooting up from his ankle. The angry female hissed, exposing three-inch long, curved fangs dripping with poison. She flared the fleshy spines on her jaws, and reared back, prepared to strike the fallen man.
From Spock's position, looking on at the scene, he was able to notice a curiously soft depression in the creature's thick layer of scaly armor. Over its breast, in front of its left foreleg, was a patch of skin unprotected by any natural defenses. The Vulcan may have been able to deduce the cause of the sore as a purulent fungal infection, but at that moment, all he could think about was saving his captain. As the creature, with a roar, lunged forward to pick Kirk up with stabbing teeth, Spock grasped his phaser and took careful aim. He pulled the trigger, and with a flash of light, hit his mark perfectly. The reptile, stunned, crashed to its side, releasing the captain from its deadly grip.
"Shiiiiit..." Kirk moaned, crawling away from the still-dripping fangs. He was in pain; he couldn't think through the pain. His ankle was obviously broken, as it was swelling up underneath his boots. Poison from the creature's spit and teeth further inflamed the ragged gashes in his sides, but at the same time spread a numbing paralysis through his central nervous system. He was already starting to lose the feeling in his throbbing ankle.
Spock knew he would have to move fast. Neither of them had their communicators (Spock's had been dropped during their run and Kirk's was crushed between the creature's back teeth), so it was vital that Spock figure out the location of the landing site and carry Kirk to that location, and quickly. The captain's breathing was growing weaker.
The commanding officer observed what little of the sky he could see through the canopy of green leaves and sickly-smelling blossoms, searching for a clue that might indicate direction. The sun, still rising in the East, was to Spock's right. He knew they had made camp to the West, and so, assuming they hadn't bypassed the landing site already during their mad chase through the swamp, it should be no more than a mile onwards. Hauling Kirk over his shoulder, he dashed off, ignoring the pain from his own throbbing wounds.
Spock arrived at the landing site just in time to save Kirk's life. Upon entering the camp, he commed Mr. Scott and ordered him to beam them onto the ship immediately. Scotty did them one better: back aboard the Enterprise, Spock found Dr. McCoy waiting to rush Kirk to the medical wing. Three agonizing hours later, the captain was in stable condition: the poison had been drawn out of his system, wounds thoroughly cleaned and closed, and ankle tightly reset and bound. Even Spock's wounds were neatly stitched up.
Later, Kirk and Spock, still resting in the sick bay while Bones stood near sipping a glass of scotch, discussed their mission. There was still much to do on the planet's surface, including a taxonomic evaluation of the native flora and fauna, but now they knew that precautions needed to be taken to ensure the safety of the ground crew. Spock began to suggest a plan that he had been formulating that would hopefully do the trick, but Kirk interrupted.
"Look, buddy, I know you need my approval to set up any official safety procedures, but I feel like shit right now, so I'm going to trust you to do it without me. Got it?"
Bones looked on in amusement as Kirk caught his friend's wry glance and realized that Spock had been kidding.
Kirk snorted. "Oh, you're funny." He stuck out his tongue at Spock, prompting a laugh from McCoy and an eye roll from the first officer.
As the three friends shared in each other's company, they were content. Their analysis of the new planet awaited them, but they knew they could take a day to recover from their injuries. In the meantime, the good doctor was in possession of some aged Romulan ale that at least two of them would be happy to partake of.
All was well.