After defeating the Titans, the gods divided the world among themselves; Zeus took the skies, Poseidon the seas, and Hades, tricked by Zeus, was left with the Underworld. The gods created the mortals, whose worship maintained the god’s immortality. Over time, however, the mortals begin to question and resist their creators. King Acrisius leads an assault on Mount Olympus itself. Zeus disguises himself as Acrisius and sleeps with his queen, Danae, who conceives and bears a son, Perseus. Angered, Acrisius has Danae and Perseus locked in a chest and thrown into the ocean. Zeus punishes Acrisius by transforming him into the deformed creature Calibos. A fisherman named Spyros hauls the chest out of the sea and finds baby Perseus and his now-dead mother. Spyros and his wife raise Perseus as their own son. Years later, an adult Perseus and his family watch as soldiers from the city of Argos destroy the statue of Zeus, declaring war on the gods; the Furies are then unleashed on them. Hades appears and destroys the family's fishing vessel; Spyros and his family drown, with Perseus as the only survivor. Found by another group of soldiers, Perseus is brought before King Cepheus and Queen Cassiopeia, celebrating their campaign against the gods. Queen Cassiopeia boasts that her daughter Andromeda’s beauty is greater than Aphrodite. The revelry is interrupted by Hades, whom Zeus has given leave to punish the mortals for their defiance. Hades threatens to unleash his monster, the Kraken, against Argos, unless Andromeda is offered as a sacrifice. Before leaving, he also reveals that Perseus is the demigod son of Zeus. Perseus meets Io, a mysterious girl cursed with agelessness, who confirms his origin. Perseus, Io, and the King's Guard journey to the Stygian Witches, seeking a way to defeat the Kraken. To help his son, Zeus gives Perseus a sword forged on Olympus. Perseus refuses it, but the captain of the guard, Draco, keeps it. Soon after, they are attacked by Calibos. Draco severs Calibos's hand, forcing him to flee. The group gives chase but Calibos’s hand and drops of his blood transform into giant scorpions. They are saved by a band of Djinn, non-human desert sorcerers, who tame the remaining scorpions. Also wishing for the gods' defeat, the Djinn lend their aid to Perseus and his band. As they continue to travel, Io aids and teaches Perseus and they begin to fall in love. The group arrives at the lair of the Stygian Witches and learn that to kill the Kraken, they must obtain and use the head of Medusa, a gorgon who resides in the Underworld. Any living creature that looks on Medusa's eyes will turn into stone. Soon after, Zeus appears to Perseus and offers him a place among the gods, which Perseus rejects. Reaching the Underworld, the men enter Medusa's temple lair, while Io remains outside. Medusa kills everyone except Perseus, who finally manages to behead her by using his reflective shield to see her with his back turned. As he leaves the temple, Calibos appears and fatally stabs Io. As Perseus and Calibos fight, Perseus picks up the Olympian sword and stabs Calibos, restoring his human form; with his last breath, Calibos urges Perseus not to become a God. As Io lies dying, she urges Perseus to leave her and save Andromeda and Argos. The winged horse, Pegasus, arrives and takes Perseus back to Argos as Hades releases the Kraken. Prokopion, a fanatic worshipper of Hades, and his cult seize Andromeda to sacrifice her. Meanwhile, Hades reveals that he seeks to take revenge on Zeus for trapping him in the Underworld; weakening him by eliminating the mortals. Perseus arrives and exposes Medusa's head to the Kraken, who gradually petrifies and crumbles. Prokopion attempts to kill Perseus, but Cepheus stops him and is stabbed; both are then crushed by Kraken's falling claw. Hades confronts Perseus, but Perseus, invoking Zeus, hurls his sword at Hades, forcing him back to the Underworld. Perseus rescues Andromeda, who asks Perseus to rule Argos by her side as King, but he declines. Perseus later refuses another offer of godhood from Zeus; instead, Zeus revives Io, reuniting her and Perseus.
