The fisherman, Spyros, finds a casket afloat in the sea advertent the babyish Perseus and his asleep mother, Danaë, inside. Spyros decides to accession Perseus as his own. Years later, Perseus and his ancestors are fishing aback they attestant a accumulation of soldiers from Argos antibacterial a massive bronze of Zeus and declaring war on the gods. Following the abatement of the bronze Hades commands harpies to annihilation the soldiers again rises from the ocean antibacterial the baiter Perseus and his ancestors are on. Perseus fails to save his ancestors and passes out on driftwood. The actual soldiers booty him aback to Argos.
During a barbecue for the abiding soldiers Baron Cepheus and Queen Cassiopeia of Argos analyze themselves and their daughter, Andromeda, to the gods. Hades appears and kills the actual soldiers but Perseus is unaffected. Hades realizes Perseus is a demigod and reveals Zeus is his father. Hades kills the queen, and threatens that in 10 days, the Kraken will be appear and if angel Andromeda is not sacrificed Argos will be destroyed.
The Argives see Perseus as an abettor of the gods and apprehend him but the baron seeks his advice extenuative his daughter. Io, who has been watching over Perseus his absolute life, advises him to advice the king. Perseus embarks to acquisition the Stygian Witches with a accumulation of soldiers, their baton Draco, and Io. Hades enlists Acrisius, a agee man who was affiliated to Danaë aback Zeus abounding her with Perseus. Aback Acrisius planned to annihilate his wife and the new built-in Perseus, Zeus beatific bottomward a arrow from Olympus, abominably scarring and disfiguring Acrisius's absolute body. Acrisius tells Hades: "There is no Acrisius; alone Calibos." Hades imbues Calibos with all-powerful admiral to aid him in killing Perseus. Calibos attacks the group, aback his duke is burst the claret hits the beach and creates behemothic scorpions. Perseus and the Argives administer to annihilate the aboriginal two scorpions, but are amidst by three more. As they are about to attack, the scorpions are aback calmed by a accumulation of Djinn, Sand-Demons with bewitched powers. There is initially apprehension amid the two groups, until the arch heals Perseus and the two abandon accede to cooperate.
At the bouldered Garden of Stygia the three Stygian Witches acquaint Perseus that Medusa's arch will be able to annihilate the Kraken, but he will die in the process. Afterwards abrogation the witches Perseus talks to Zeus who offers to accomplish Perseus a god but he refuses. Zeus understands that he can not change Perseus's apperception and gives him a aureate drachma. Persues uses the bread to allurement Charon (Ferrier of the dead) for access into the Abyss and they access Medusa's lair. Medusa turns all the actual soldiers into stone, the Djinn destroys himself with his heart, abrasion Medusa. Draco, who is afflicted by one of Medusa's arrows, rescues Perseus by skewering Medusa with a bean colonnade from the ceiling. He allows himself to be angry to bean to accord Perseus a bright attempt at Medusa's head. Perseus kills Medusa, but as he exits the temple, Calibos stabs and kills Io. Perseus fights and kills Calibos, axis him aback into Acrisius in animal form. Perseus takes Pegasus aback to Argos area the Kraken is antibacterial the city.
Hades confronts Zeus answer that while the added Gods await on the bodies adulation and adoration for power, over time he has become able to augment off their abhorrence and hatred. The abolition of Argos will briefly accord him abundant ability to abolish all of the Olympians at once. Zeus attempts to banish Hades aback to the underworld, but Hades already has abundant ability to defeat Zeus. Hades bound overpowers him but an afflicted Zeus reveals that Persues lives. Hades is affronted and leaves to baby-sit the Kraken's advance and ensure victory.
Hades commands his creatures to advance Perseus and abduct Medusa's head. Perseus defeats the creatures and regains the head, as able-bodied as auspiciously axis the Kraken to bean afore it consumes Andromeda. Hades appears already added and boasts that he cannot die because he is immortal; but Perseus throws his sword, answerable calm with a bolt of lightning from Zeus's which banishes him to the Abyss as the achievement of the bodies afterwards the Kraken's defeat allows Zeus to achieve his strength. Perseus again saves Andromeda from drowning aback the accoutrement acclimated to arrest her avalanche into the ocean, but refuses to become baron of Argos.
Zeus appears and offers to accomplish Perseus a god on Olympus, but he refuses. Zeus addendum that Hades will acknowledgment one day for animus aback flesh is in fear. Since Perseus is absorbed to break on Earth, Zeus resurrects Io.
* Sam Worthington as Perseus capital protagonist, and son of Zeus
* Liam Neeson as Zeus, the baton of the Gods of Mount Olympus
* Ralph Fiennes as Hades, God of the Abyss and the primary villain
* Gemma Arterton as Io
* Alexa Davalos as Andromeda
* Izabella Miko as Athena
* Mads Mikkelsen as Draco, baton of the Praetorian Guard
* Jason Flemyng as Acrisius/Calibos
* Danny Huston as Poseidon
* David Kennedy as Cepheus's General
* Tamer Hassan as Ares
* Pete Postlethwaite as Spyros
* Polly Walker as Cassiopeia
* Vincent Regan as Cepheus
* Luke Treadaway as Apollo
* Nathalie Cox as Artemis
* Nina Young as Hera
* Kaya Scodelario as Peshet
* Nicholas Hoult as Eusebios
* Ian Whyte as Sheik Suleiman
* Agyness Deyn as Aphrodite
* Paul Kynman as Hephaestus
* Alexander Siddig as Hermes
* Charlotte Comer as Demeter
* Jane March as Hestia
* Natalia Vodianova as Medusa
* Hans Matheson as Ixas
* Mouloud Achour as Kucuk
* Liam Cunningham as Solon
* Ross Mullan as Pemphredo