Commander Adams (Leslie Nielsen) and his crew set out to investigate the disappearance of a colony of scientists on the planet Altair-4. After landing, they discover only two survivors, Dr. Edward Morbius (Walter Pidgeon) and his exquisite daughter Altaira (Anne Francis).

The Morbiuses live a surprisingly prosperous lifestyle, attended to by Robby the Robot, a super-butler who performs many amazing feats. But lurking in the background is an invisible force -- which may or may not have been responsible for the disappearances of those scientists – and about which only Morbius knows the truth. But Morbius is not about to share his secret (or his daughter!) with anyone else.