Perseus (Harry Hamlin), son of the Greek god Zeus (Laurence Olivier), grows up on a deserted island. His destiny is to marry Princess Andromeda (Judi Bowker), who will someday rule the city of Joppa.

But as long as the satyr Calibos (Neil McCarthy) -- who uses a giant vulture to kidnap Andromeda's soul every night -- is alive, no one can marry her. Perseus travels to Joppa, where he must defeat Calibos and other mythological monsters to rescue Andromeda.

Along the way, Perseus is granted a "loan" of one of the other Greek Gods' familiar, a very wise and normally talkative owl. However, the Goddess in question has fashioned (for her, she says) a "mechanical owl" that only Perseus can understand its "clickling, whirring, talking". Said "Mechanical Owl" was mentioned in the 2010 version of this same film while the party of "heroes" were packing. The Group's Leader says "Take Everything". A soldier asks "What about this?" (The Mechanical Owl). The reply is "Oh, you can leave that here."

Also mentioned in this film are the giant, man-eating (and man-sized) scorpions, Medusa, the Invincible Sword, the Impenetrable Shield, and so forth. Perseus (in this film) seems much more grateful to have the Greek Gods "help" than later incarnations of this story.