Traveling the countryside, Xena and Gabrielle encounter a twelve-year-old seer with a startling prophecy. She warns them about a mage whose well-intentioned spell will lead to disaster. The spell will unleash Cerberus, the fearsome guardian of Hades' gates. The mage seeks relief for those who suffer in the underworld. But his spell will set free many evildoers - as well as Cerberus himself - to terrorize the earth.

Xena and Gabrielle must help the seer break the spell - before all Hades breaks loose.

But more danger awaits. Because according to the prophecy, one of them will not return...