When the Philistines attack, the Israelites are hopeless against the fierce giant Goliath and don't know what to do. King Saul takes the advice of the prophets and sends an adolescent shepherd, David, into battle to conquer the oversized Philistine. David is victorious and becomes the King of Israel.

Upon his return from battle in the previous film, the great warrior Hercules learns that his lover, Daianara, has lost her senses. According to 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.

Krios, the youngest of the Titans, may be the least strong of the seven brothers whose strength comes from their mother, earth-goddess Gaia, but is by far the smartest, and thus their natural leader. He arrives on Crete, the kingdom of the mighty king Minos, impresses him as gladiator, gains his trust, falls in love with a mortal girl and discovers both Minos's human sacrifice-cult and a foreign conspiracy to seize power with a hidden army.

Strongman Maciste must battle the one-eyed Cyclops monster that is ravaging the land of Sadok, while at the same time fending off the advances of the evil Queen Capys, who wants to do a little ravaging of her own.

Rome chafes under the rule of the Emperor Domitian and his Egyptian mistress, Artamne. A mysterious champion arises to fight against the Emperor -- a masked man known as the Red Wolf. In fact, the Red Wolf is Valerius Rufus, one of the Emperor's trusted centurions who's aided by none other than the Emperor's court jester, the diminutive Elpidion. Rebels in league with Valerius kidnap Artamne, planning to exchange her for two of their imprisoned colleagues, but Artamne escapes and soon both Valerius, (now exposed as the Red Wolf), and his fiancee, Lucilla, are sentenced to be immersed in a cauldron of molten lead. Valerius's friends, however, rise up to rescue him and to liberate Rome.