Explorers We
Explorers We is a science fiction short story by Philip K. Dick. First published in Fantasy and Science Fiction magazine, January 1959.
In this story some aliens come to Earth as perfect replicas of a group of astronauts who died during a mission to Mars. The astronauts seem to be utterly convinced they are humans and they do not understand why the FBI chases them after they have 'come back' to Earth. Humans only know that these astronauts are not the same as those who originally left for Mars, and nothing more. The original astronauts could have been saved and/or cloned by the aliens. The disguise could be a way to try to communicate more easily with the earthlings. Still other factors could explain these perfect copies of human beings, but the earthlings have no intention of investigating them. Above all, the possible threat must be eliminated, and only then questions can be asked. At the end of the story, Wilks, an FBI agent, poses the central question raised by the story: