The film begins with a narration that explains the three Olympians who battled the Titans long ago:Zeus, Poseidon, and Hades. Hades provided their means of defeating the Titans with his creation, theKraken. After the Titans' defeat, Zeus created humans and ruled them while Poseidon ruled the sea, but Hades, having been deceived by his brother Zeus, was forced to rule the Underworld, learns an alternative way of gaining power from humans different from his brothers receiving theirs from human prayer: through fear.
Millennia later, an angry king who destroys all the ancient statues of gods. Gods get angry with him and want to kill him. But, Zeus tells them that they will punish him instead. So, Zeus in the form of the king rapes his wife Danae. The king gets angry and puts Danae and the newborn child, whose name is Perseus, into a coffin in the sea. Danae dies but Perseus is found and raised by a fisherman named Spyros.
Years later, Perseus and his family are fishing when they witness a group of soldiers from Argos destroying a statue of Zeus as a declaration of war against the Gods. Hades appears and commands harpies to massacre the soldiers before he himself destroys Perseus' family's fishing boat. Perseus tries to save his family but it is late. Τhe surviving soldiers take Perseus back to Argos.
The whole film shows the battle between Perseus and Hades and the difficulties that Perseus meets to beat Hades. In the end, Perseus sends Hades back to Underworld, because Hades is immortal and cannot die.