A scientist receives a very unique message that only he is able to view due to his expertise. A colleague of his, presumed dead, writes him saying he is not only alive, but was taken by aliens. These aliens have been greatly harmed by unknown side effects of cold war atomic testing. Though not violent, they have a plan to stop it, unless Earth heeds the warning. Written in in 50's, this is a short story originally cared in Amazing Stories magazine.
A sampling of the text “Forster was a nervous, over-conscientious little man, and his day was already ruined, because any departure from strict administrative routine worried and upset him. Only in his field of aviation medicine did he feel competent, secure.
He knew that around the center they contemptuously called him "Lilliput." The younger researchers were constantly trying to think up new ways to play jokes on him, and annoy him.
Crawley Preston, the research center's director and his chief, had been summoned to Washington the night before. Forster wished fervently that he was around to deal with this matter. Now that relations between East and West had reached the snapping point, the slightest deviation from security regulations usually meant a full-scale inquiry. He signed for the container, and carried it out to the car, still seething impotently over the guard's insolence. He placed it beside him on the front seat of his car and drove up to the building which housed part of the labs and also his office. He climbed out, then as he slammed the door he happened to glance into the car again. The seat covers were made of plastic in a maroon and blue plaid pattern. But where the box had rested there was a dirty grey rectangular patch that hadn't been there before.
Forster stared, and then opened the door again. He rubbed his fingers over the discolored spot; it felt no different than the rest of the fabric. Then he placed the box over the area it fitted perfectly. He flopped down on the seat, his legs dangling out of the car, fighting down a sudden irrational wave of panic. He pushed the container to the other end of the seat.
After all, he rationalized; plastics are notoriously unstable under certain conditions. This is probably a new alloy Washington wants tested for behavior under extreme conditions of temperature and pressure. What's gotten into you?