Hercules returns from a series of adventures to find his lover, Princess Deianira, in a catatonic state. The kingdom's oracle reveals that her condition is due to her missing soul, which has been imprisoned in the realm of Hades. Determined to save her, Hercules, along with his loyal friend Theseus and the comical Telemachus, embarks on a perilous journey to the underworld. On their way, they face numerous supernatural challenges, including deceptive sorcerers and nightmarish creatures that test their strengths and wits.

Upon reaching Hades, Hercules discovers that the evil King Lico is behind Deianira's affliction. Lico seeks to exploit Deianira's soul to increase his own dark powers. To rescue her, Hercules must confront Lico and navigate through an intricate maze of perilous traps and diabolic conjurations. As tensions rise and betrayals become imminent, Hercules realizes that physical strength alone will not suffice; he needs to outsmart his enemies and draw upon inner resilience. The journey is fraught with moral dilemmas and ancient curses that push Hercules to his limits, setting the stage for an epic confrontation in the heart of the dark underworld.