-by Richard Landau

When two oceanographic vessels disappear in the Aegean Sea, the Seaview goes to investigate and is led to the discovery
of a hostile city beneath the sea.

Admiral Nelson and Captain Crane make slow progress in searching out an explanation for the disappearance of two research ships in Aegean waters until Crane, an expert
diver, meets another expert, a girl, Melina.  is persistent inquiries, after her father has been mysteriously killed while diving, lead to a visit from a wheel chair invalid, Zeraff, who says he wants to hire a diver. There is treasure in the sea below, he says. Crane, scenting a lead, takes the job, dons scuba gear, but finds kidnappers instead of treasure as he is captured and carried through the locks of a dazzling city beneath the sea. It's Zeraff's creation, and the means by which he intends to conquer the world. When Melina is brought there too, Crane conspires with her to escape the city, but as they get away they are seen and followed, and Zeraff himself tries to recapture them, but the Seaview, which has been on Crane's trail all along, appears in time to rescue the pair as Zeraff impales himself on his own spear, and when the city opens fire on the sub, Nelson answers with torpedoes that demolish the undersea marvel.

CAST
Adm. Harriman Nelson Richard. Basehart
Commander Lee Crane David Hedison
Chief Curley Jones Henry Kulky
Lt. Cmdr. Chip Morton Robert Dowdell

GUEST CAST
Zeraff Hurd Hatfield
Melina Linda Cristal
Round Face John Anderson

Executive Producer Irwin Allen
Director James Braham