Helium:

Helium.

It was all over the place, and the ship was reeling. The only one who seemed to know anything about it was Jim.

Chekov, whose voice was already high, sounded very much like a cartoon character. Spock sounded like a complete idiot, trying to talk like his normal self with a voice so much higher than normal. Poor Bones was practically refusing to speak and communicating through sign language unless absolutely necessary.

And then there was Jim.

Jim happened to have found a gas mask in time (the only one on the ship, imagine that!) and begun to wear it around to prevent the side-effects of helium and the only thing that he would say, in a very loud, British-accented voice, was, "Are you my mummy?"

When asked, Bones only shrugged and managed to convey, "It could've been anything. My money's that it was Jim."

And so it had been. Jim had somehow managed to find a way to fill the entire ship with a breathable version of helium - but with the same high-voice effects.

Finally, after the entire ship had endured four straight days of the helium, it began to filter out of the system, which actually made it funnier. While people were mostly talking in normal voices, the helium would come along unexpectedly and cause their voices to jump.

It was only after the third day of filtering that it almost vanished completely, and Jim took his gas mask off to celebrate. The issue was, nobody could prove that Jim had done anything, even with the incriminating idea of the mask.

And so life went back to normal on the Enterprise, with everybody talking normally again. On the bridge, Jim was talking in his patented "Captain's voice" when suddenly, along came a little bubble of his helium and his voice suddenly flew up an octave.

And the bridge crew fell to pieces laughing, while Jim looked embarrassed, and Spock, in his very Vulcan way, seemed to be thinking along the lines of "payback."

Just a cute little oneshot on what would happen if Jim filled the ship with helium. Duh. With a little Doctor Who reference for my Whovian friends. Love my Jimmy! Please review!