As friends of young scientist Schuyler Davis and his girlfriend Diane (Vicki Trickett), the Three Stooges help build a time machine that carries them all back to ancient Ithaca. When King Odius, promptly takes a liking to Diane, he ships Schuyler and his friends off to the galleys to get them out of the way. Though he's made a slave aboard the ship, Schuyler works so hard that he soon becomes a muscleman and, when they escape, the Stooges begin promoting him in local gladiatorial contests as "Hercules." Once the real Hercules appears, things look bad for the Stooges. But when they finally persuade Hercules to help them in a palace coup against Odius, Diane is rescued and all happily return to the 20th Century.