Anderson Poul. Time Patrol

The work is, you understand, somewhat unusual, said Mr. Gordon. And confidential. I trust you can keep a secret?
Normally, said Manse Everard. Depends on what the secret is, of course.
Mr. Gordon smiled. It was a curious smile, a closed curve of his lips which was not quite like any Everard had seen before. He spoke easy colloquial General American, and wore an undistinguished business suit, but there was a foreignness over him which was more than dark complexion beardless cheeks, and the incongruity of Mongolian eyes above a thin Caucasian nose. It was hard to place.
We’re not spies, if that’s what you’re thinking, he said.
Everard grinned. Sorry. Please don’t think I’ve gone as hysterical as the rest of the country. I’ve never had access to confidential data anyway. But your ad mentioned overseas operations, and the way things are — I’d like to keep my passport, you understand.
He was a big man, with blocky shoulders and a slightly battered face under crew-cut brown hair. His papers lay before him: Army discharge, the record of work in several places as a mechanical engineer. Mr. Gordon had seemed barely to glance at them.
The office was ordinary, a desk and a couple of chairs, a filing cabinet, and a door leading off in the rear. A window opened on the banging traffic of New York, six stories down.
Independent spirit, said the man behind the desk. I like that. So many of them come cringing in, as if they’d be grateful for a kick. Of course, with your background you aren’t desperate yet. You can still get work, even in… ah, I believe the current term is a rolling readjustment.
I was interested, said Everard...