Thomas, a vagrant

Thomas spun the pistol in his hands, thinking of the absurdity of it all. He was camping out in the woods the last night when a loud explosion woke him up. Soon he found the aftermath of the sound - a burning wreckage.

It was too small to be a plane. Perhaps it was a government spy drone, he thought, and began to investigate the wreckage for any clues. It was at this moment that a hatch popped open, and he saw a small green humanoid raise a silver object at him.

Military instincts took over, and he dove to the side just as a rainbow coloured beam lanced through the air he stood a second ago. Thomas scrambled behind a tree, his heart pounding. He couldn't believe his eyes.

Hearing nothing even after a full minute, Thomas peeked out. The creature that shot at him was still in the wreckage, except it was lying face down and not moving.

"No fucking way... it's really an alien?"

His eyes landed on the weapon the alien held and pulled it away for safety. Though made for much smaller hands, he just barely managed to fit his finger into the trigger.

His ears picked up the sounds of a distant siren, and he decided he didn't want to be involved in whatever this is. And so here he was, sitting on the curb with this alien gun.

It wasn't a weapon, at least not in the traditional sense. Firing it at walls did absolutely nothing. Thomas fiddled with a few buttons on the gun and found out it had a handy instruction manual in English.

"New user detected. Language setting: English. Please state your query."

"How do you know English?"

"The knowledge was scanned from your memory matrix."

"What are you?"

"I am a infiltration tool, designed to help agents pass as a member of the local population. Please point me at a desired target and pull the trigger. The target will be downloaded to my registers, and I will apply its identity to you."

"Downloaded? What happens to the target?"

"They are indefinitely stored in my registers until you wish to release them. I am capable of storing up to three beings of your quantum complexity."

That was an interesting usage and much better than a simple weapon, Thomas thought.

"So you're saying I can transform into other people?"

"Incorrect. Only perception will be altered. All members of the target species will believe you are the target, even when your physical attributes differ. The perception altering field also has the benefit of making the target species trust you more."