Hercules comes from Greece to Ravenna, Italy, because a friend from childhood days has sent for him: Hercules should help the Roman Emperor who is in danger because of an intrigue lead by the leader of the pretorian guards.

A scientist who has invented a weapon capable of disintegrating solid matter is kidnapped by a criminal gang, which intends to sell the scientist and his weapon to the highest bidder. A secret agent and the scientist's daughter set out to track down the kidnappers and rescue the scientist.

In 54 B.C. Julius Caesar seeks to solidify his position in Rome by putting down a rebellion in Gaul led by a tribal chieftain named Vercingetorix. Vercingetorix has rallied many tribes to his cause, including one led by the beautiful Queen Asterid and others who'd once pledged allegiance to Rome.

Hercules is summoned to oppose the evil Queen Samara, who has allied herself with aliens and is sacrificing her own people in a bid to awaken a moon goddess.