Time

Martin sat in an old office chair. It didn't seem odd in the New Old West saloon. End o' the world and all, he thought.
He knew them the moment they walked in. The man and woman were dressed right, but out of place.
"Evenin'" Martin said casually.
"We understand you buy new technology," the man said
The lanky woman reached under her poncho and held a small black rectangular object out to him.
Martin looked at it , said, "OK, I give up. What's it do?"
The man dropped something, and there was a blinding explosion. "Flash-bang," Martin thought as he holstered his pistol.
He scooped up the black rectangle, shoved it in his pocket and left.
Back at his house Martin, looked at the device, set his drink down. He pulled out a cheroot, lit it, examined the device closely.
His thumb ran along the flat surface and everything got loud suddenly. There was a blast and white light and the room disappeared.
Martin felt rapid movement, said, "Another mission," and was gone.