When the game starts, Kratos has been serving the gods for ten years. He kills the Hydra on behalf of Poseidon, but he has grown tired of his service and suffering. He summons Athena, who states that if Kratos performs one final act—the murder of Ares—he will be forgiven for killing his family. Ares is waging war on the city of Athens out of hatred and jealousy of his sister Athena, who assigns Kratos to destroy Ares because Zeus has forbidden divine intervention. Athena guides Kratos to the war-torn Athens. After a strange encounter with a gravedigger who encourages him to continue his task, Kratos battles his way to Athens's oracle, finds her, and learns that the only way to defeat Ares is with Pandora's Box, a mythical artifact that grants the power to kill a god.