The ruthless Roman tribune, Vadio, joins forces with the evil Morakeb to take over the throne of Aristea, usurping King Krontal and stealing away his lovely daughter in the process. Meanwhile, Marco Aulo, now a Roman centurion, comes to Aristea to learn where his legions war funds have gone. Vadio has him framed for treason and is thrown into the arena to fight a group of six formidable gladiators. During the fights, Marco refuses to kill those he defeats until finally, he himself loses after exhaustion takes its toll. Admiring this man, the six warriors join him and together they escape Vadio's clutches and plot to free the kingdom from the two conspiring killers. Edited from Mole Men Against the Son of Hercules

The eternal Hercules in this film has gone way beyond his usual time and place in ancient Greece and is now helping Poland free itself of Mongol invaders in the 12th century. Mark Forest is the star of this peplum epic, Hercules Against The Barbarians.