"Goddamnit Jim! Stop that!"

"Oh come on Bones; you can't honestly tell me you're not having fun."

"Fun?"

It was well past eleven o'clock, and most of the crew had returned to the ship after a relaxing day of shore leave.

The sun had set about four hours ago, but the moon and stars gave them all the light they needed. And Jim Kirk wasn't quite through having fun yet.

Jim stood up and jumped as high as he could, landing on his stomach in front of his best friend. The resulting shockwave that his leap created was sent through the trampoline towards the doctor, and he was promptly knocked over.

"Yeah, fun. You do know what that is, right?" Kirk gave a devilish grin as he continued to bounce about on the stretched elastic. McCoy watched him, wondering if he was looking at a Starship Captain or a five-year-old boy.

"Well I don't know what the hell is so 'fun' about jumping around on a screaming deathtrap like this thing. You know how easy it would be to get killed on one of these? One slip and your neck snaps. Land on the wrong vertebra and you're paralyzed for life. Accidentally hit your skull on the metal frame, and your memory's wiped clean. Just—"

"Bones. Shut up," Kirk said defiantly, illustrating his point by doing a perfect back flip.

This resulted in a sharp intake of breath from the doctor as he watched Jim prance about the trampoline. "I'm not kidding Jim…" he trailed off, accepting that Kirk was simply not going to listen.

To be honest…it really wasn't that dangerous; he just didn't want Jim to get hurt. Damn his maternal instincts…

McCoy was now content to watch Kirk bound and flip all over the place. But Jim soon realized that it wasn't really as much fun doing it by himself. "Come on Bones! Get up!" he encouraged playfully.

Leonard showed a certain amount of reluctance, having no desire to jump around like a madman.

Jim gently grabbed his wrists and pulled him to his feet. "Here, we'll start together."

Despite everything that his instincts were screaming at him, Bones conceded and decided to try and have some fun. Still guiding him by his wrists, Jim began to lightly move up and down, feet not breaking contact with the surface of the trampoline. Bones was now the one that felt like a five-year-old.

"See, it's not so scary," Jim teased. He began to bounce higher and higher, but still maintained contact with the elastic ground. As Jim jumped higher and faster, Bones was forced to follow suit, for Jim was showing no sign of letting go of his wrists…well, by now, his grip had moved to Leonard's hands.

After a few minutes, McCoy finally started to loosen up and enjoy himself.

It actually was kind of fun…in a completely ridiculous and childish way, of course.

But in spite of himself, Bones soon found himself bouncing and laughing right alongside his best friend. It seemed as if they kept at it for hours, perfectly content to inhabit the realm of a child for just one night.

If anyone had happened to be walking outside that night, they would have only seen two best friends, reliving the childhood days that they never got to share, rejoicing in the simplicity of the other's company, and holding onto each other like the brothers that they were.

When dawn broke, the sun crept over the horizon to reveal two bodies, fast asleep on the trampoline, hands still clasped tight.