When a volcano erupts, a deep-sea vessel full of scientists suffers damage and begins to lose control. To their rescue comes Captain MacKenzie (Joseph Cotton, CITIZEN KANE), commander of Alpha, a high-tech atomic submarine. The captain takes the crew to a secret underwater utopia called "Latitude Zero" that is dedicated to the preservation and protection of mankind. With a completely opposite agenda, the evil Dr. Malic (Cesar Romero, The Joker from TV's BATMAN) wishes to kidnap and experiment on the scientists in order to add to his roster of super-intelligent freak minions. Now it's up to Captain MacKenzie and his crew to save the day.