A young boy, Charlie, discovers that his father is not actually his father. The man in his house who comes home from work, kisses his mother, sits down to dinner, makes comments about his day at the office may look and talk like the real Mr. Walton, but Charlie knows better. He alone knows the hideous secret: that his real father has been killed, and that an alien now inhabits his body, and has usurped his life. It is no longer his father but the "Father-Thing."

Published in The Magazine of Fantasy and Science Fiction, December 1954. Reprinted in:

• Isaac Asimov Presents the Great SF Stories: 16 (1954) (1987), ed. Isaac Asimov & Martin H. Greenberg, DAW 1987
• The Collected Stories of Philip K. Dick, Vol. Three: The Father Thing, Underwood-Miller 1987
• Urban Horrors (1990)
• The Collected Stories of Philip K. Dick, Volume 3: Second Variety, Carol Publishing Group/Citadel Twilight 1991
• Nursery Crimes, ed. Stefan R. Dziemianowicz, Robert Weinberg & Martin H. Greenberg, Barnes & Noble 1993
• Between Time and Terror, ed. Robert Weinberg, Stefan Dziemianowicz & Martin H. Greenberg, Penguin/Roc 1995
• A Century of Science Fiction 1950-1959, ed. Robert Silverberg & Martin H. Greenberg, MJF Books 1996
• The Philip K. Dick Reader, Carol Publishing Group/Citadel Twilight 1997
• The Young Oxford Book of Aliens, ed. Dennis Pepper, Oxford University Press 1998