The story of the man who thought he was the greatest lover in the world... and the people who tried to cure him of it!
John R. DeMarco, a man who believes himself to be Don Juan, the greatest lover in the world. Clad in a cape and domino mask, DeMarco undergoes psychiatric treatment with Dr. Jack Mickler, to cure him of his apparent delusion. But the psychiatric sessions have an unexpected effect on the psychiatric staff, some of whom find themselves inspired by DeMarco's delusion; the most profoundly affected is Dr. Mickler himself, who rekindles the romance in his complacent marriage.