|Season 1, Episode 16|
|Air date||January 13, 1964|
|Written by||Leslie Stevens (uncredited)|
|Directed by||Leslie Stevens (uncredited)|
Don't Open Till Doomsday
"Who hasn't seen the dark corners of great cities, whose small and shabby creatures wander without purpose in the secret corners of the night? Without purpose? There are those whose purpose reaches far beyond our wildest dreams."
"Who knows? Perhaps the alteration of one small event may someday bring about the end of the world. But that someday is a long way off, and until then there is a good life to be lived in the here and now."
- Barry Morse — Phobos One
- Carroll O'Connor — Deimos
- Grace Lee Whitney — Carla Duveen
- Robert Fortier — Bert Hamil
- Robert Kelljan — Frank Brant
- Linda Hutchins — Arlene Schnabel
- Leslie Stevens — voice of Martian Computer Control (uncredited)