"Clash of the Titans" is derived from classical Greek mythology and follows the exploits of the semi-divine hero, Perseus. In particular, it addresses his journey to save the maiden, Andromeda, from the titanic sea monster, the Kraken. In the attempt, Perseus also finds himself caught in a feud between the gods.
The story first explains Perseus' background, indicating that he is the son of the mortal woman, Danaë, and the chief god, Zeus. Ultimately, this semi-divine pedigree provides the source of Perseus' extraordinary cunning, bravery and strength. Perseus eventually finds himself in the court of King Cepheus and Queen Cassiopeia, who, in their impious battling against the gods, have invoked the wrath of Hades, lord of the underworld. To punish these rulers for their impenitence, Hades offers them a choice: have their entire city face the Kraken or offer their daughter, Andromeda, as a sacrifice instead.
Desperate to save their daughter, the rulers charge Perseus with her rescue. Along the way, Perseus encounters a slew of supernatural creatures, gains the aid of his father Zeus and is gifted several magic items, including an Olympian sword and a winged horse named Pegasus. Perseus' most serious test is killing the serpent-headed Gorgon, Medusa, whose head he can then use to turn the Kraken to stone. Perseus then saves Andromeda, kills the Kraken, avoids death at the hands of Hades and refuses Andromeda's offer of marriage and kingship. He lives out his days as a mere mortal with the famed lover of Zeus, Io, at his side.