Perseus was sent to retreive Medusa's head by King Polydectes, who wanted him dead so he could marry his mother. To do this, he was advised by Athena to seek the Gray sisters, who told him how to fight Medusa when he stole their eye. Hermes lent Perseus winged sandals, Hades lent him his helm of darkness (which makes the wearer invisible), and Athena lent him a shield which he could see Medusa's reflection in, since whoever looked her in the eye would turn to stone. With all these magic items, Perseus was able to cut off Medusa's head. On the way back home, he fights a sea monster to save Andromeda, who is chained to a cliff as a sacrifice, and marries her.