A marine biologist and a government agent investigate mysterious deaths and rumors of a sea monster in a secluded ocean cove, and find themselves involved with a marine biology professor conducting secretive experiments, international spies trying to steal his secrets, a radioactive light on the sea bottom, and the malevolent thing which guards it.
Kent Taylor
as Dr. Ted Stevens, alias Ted Baxter
Cathy Downs
as Lois King
Michael Whalen
as Prof. King
Rodney Bell
as William S. 'Bill' Grant
Phillip Pine
as George Thomas
Vivi Janiss
as Ethel Hall
Helene Stanton
as Wanda
Pierce Lyden
as Andy, the Janitor
Michael Garth
as Sheriff
Norma Hanson
as The Phantom
