Originally published in 1955 Jack Finney's sinister SF tale has outgrown the initial debate about whether it satirized Communism or the conformity of US society at the time, to become a classic of paranoia; an examination of our fear of 'the other'.
 
Most people know the story from seeing THE INVASION OF THE BODY SNATCHERS, the classic 1978 remake (one of the few Hollwood remakes said to better than the original, made in 1956) starring Donald Sutherland.