Hercules, Iolaus and some other former Argonauts find out that their former leader Jason is a scared drunk since he left Medea for another and saw his new family murdered; the rule of his kingdom Argos has passed to a regent. Having witnessed an apparently demon-lead party steal the Golden Fleece, they set out once again to bring it back on the Argo. Soon they strife and casualties fall but Hercules guesses the demon's identity, a rival for Jason's throne, when they're trapped in a volcano. Hera has enlisted Marcus the regent to have skeleton warriors destroy them ...