Carlo, a young doctor, occasionally meets Anna, the daughter of professor Valli. Carlo falls in love with Anna, who returns his feelings; but her father longs a brilliant marriage for her.

In order to placate the angry gods, who have allowed Thessaly to be overrun with barbarian invaders and beset with natural disasters, King Jason takes his Argonauts on a search for the fabled Golden Fleece. Meanwhile, back at home, his scheming regent is plotting to get his hands on the kingdom--and the queen.

A helicopter crashes in the desert, and the crew winds up in the underground city of Atlantis and get mixed up in a slave revolt.