Stevenson, the famous English criminal expert visits Hungary with his family. While he is chairing a conference on criminology, infamous art treasure robbers steal the golden herm of Saint László. Suspicion is cast on the Stevenson children.

On the run from the police, a female thief and her band of robbers take refuge on a desert island where they discover a mansion inhabited by a family whom they take hostage. One of the robbers falls for the couple's daughter.

Barry, a wretched playboy, expects to get rich from the legacy of an uncle of his, the king of roast meat sauce, but his lawyer informs him that the secret of the sauce recipe has been lost along with his uncle, and there is nothing to inherit except for a small island in the Aegean - called Eftychia - where his uncle came from. A hotel keeper, Richard, is interested in the island and plans to create a tourist resort on it, so the two men come hastily to Greece to arrange the sale. On the island of Eftychia they meet a beautiful young teacher, Aliki, and her mother Anna, who are determined to stop foreigners and tourist development from coming to the island. Aliki's beauty and charm seduce Barry, while Richard is enslaved by the wonderful cooking of Anna. One day while they are tasting her food, Richard discovers that Anna possesses the secret of the famous sauce, by which Barry can really become rich. Thus the island is saved, and everyone celebrates their unexpected good fortune.