An alien is dispatched from a faraway galaxy to take over the Earth by "duplicating" humans and creating a race of zombies.

George Nader
as Glenn Martin

Barbara Nichols
as Gale Wilson

George Macready
as Prof. Vaughn Dornheimer

Dolores Faith
as Lisa Dornheimer

Hugh Beaumont
as Austin Welles

Richard Arlen
as National Intelligence

Richard Kiel
as Dr. Kolos

John Indrisano
as Thor, the Butler

Ted Durant
as The Galaxy Being

Tommy Leonetti
as Reporter (uncredited)