"Stop, oh Jesus, stop," groans Bones, clutching his chest with one hand and a bottle of whisky with the other. Jim is giggling, but there's a definite hint of desperation behind his laughter that even Spock can't miss.

He raises an eyebrow incredulously – or as incredulously as one can when they're trying not to betray any hint of emotion – and watches as Jim tries to stand up, steadying himself with one hand against the cabin wall and one clutching a half-empty bottle of scotch.

Something is clearly amiss.

"I do not understand," says Spock, hands clasped neatly behind his back, as always. He allows himself to ponder the irony that the captain is making such a spectacle of himself, albeit only to the eyes of Spock and Bones. "Your behaviour is highly illogical."

At this, Jim lets out another peal of manic laughter and takes a long swig from the bottle. Bones makes a choked little noise and pours himself a shot of whisky, which he gulps down like elixir.

Spock doesn't think he'll ever understand these strange human conventions. He finds himself rather glad of this.

"I do not see what, in this situation, could be considered humorous," he continues. "Captain, may I remind you that your shift begins in eight hours? To start a shift whilst still under the ill effects of alcohol would be illogical - "

He barely manages to finish his last word before Jim slaps a hand over Spock's mouth. Remembering at the last second that it is neither customary nor acceptable to nerve pinch the captain of the Enterprise, Spock delicately removes his captain's hand from his face and takes a step back to safety. Meanwhile, Bones is sobbing in the corner, all pretence at being able to stand now lost.

"Stop… stop saying that, Mr Spock," Jim giggles. Spock does not understand. He is beginning to see a pattern emerging.

"I do not understand," he states for clarification. Jim beams widely and puts one finger over his mouth in an exaggerated gesture of secrecy.

"S'illogical," he responds, and starts giggling. If Spock were one to use similes, he might compare the captain's behaviour to that of a Terran schoolgirl, but he isn't, so he doesn't.

"It is," he concurs. "Highly illogical."

Jim takes another swig of scotch. Bones feebly attempts to pour a shot of whisky but misses the glass and it shatters onto the floor. Resignedly, he slugs the whisky neat, straight from the bottle.

Spock is beginning to understand.

"It is illogical," he repeats. Jim looks at him, wide-eyed and disbelieving, before taking another drink.

"Spock," he slurs. "Do you have Drinking Games on Vulcan?"

Spock permits himself the small victory he feels swelling in his chest and tilts his head to the side slightly, a gesture he's assured is one of innocence and naivety.

"As Vulcans do not partake in the consumption of alcoholic beverages," he states, "that would be illogical."

Bones faints.