In the 23rd century, a spacecraft travels to the distant planet Altair IV to discover the fate of a group of scientists sent there decades earlier.

When Commander John J. Adams (Leslie Nielsen) and his crew arrive, they discover only two people: Dr. Morbius (Walter Pidgeon) and his daughter, Altaira (Anne Francis), who was born on the remote planet. Soon, Adams begins to uncover the mystery of what happened on Altair IV, and why Morbius and Altaira are the sole survivors.