Upon his return from battle in the previous film, the great warrior Hercules learns that his lover, Daianara, has lost her senses. Acording of the oracle Medea, Dianara's only hope is the Stone of Forgetfulness which lies deep in the realm of Hades. Hercules, with two companions, Theseus and Telemachus, embarks on a dangerous quest for the stone, while he is unaware that Dianara's guardian, King Lico, is the one responsible for her condition and plots to have the girl for himself as his bride upon her revival.

While a Mexican revolutionary lies low as a U.S. rodeo clown, the cynical Polish mercenary who tutored the idealistic peasant tells how he and a dedicated female radical fought for the soul of the guerrilla general Paco, as Mexicans threw off repressive government and all-powerful landowners in the 1910s. Tracked by the vengeful Curly, Paco liberates villages, but is tempted by social banditry's treasures, which Kowalski revels in.