zeus travels to the underworld where he meets his brothers hades (ralph fiennes) and poseidon (danny huston) and son ares (édgar ramírez). he asks for hades' help in rebuilding the walls of tartarus, but he rejects the offer and attacks zeus. ares betrays his father, imprisons him and steals his thunderbolt. hades and ares plan to make a deal with kronos: they will drain zeus's divine power to revive him in exchange for remaining immortal. the walls of tartarus crumble and the titans are unleashed.