In the story of Perseus, king polydectes had fallen in love with Danae but Danae didn't return his feelings after thinking that Perseus would get in the way. He sent Perseus on a quest to get head of Medusa the Gorgan hoping to get rid of him.
Hermes gave Perseus a magic sword to use on his journey, and Athena gave him a mirrored shield then the nymphs of the north gave him three special gifts: winged sandals, a wallet that would expand and cap that would make him invisible.
please let me go
only if you marry me
When Perseus reached the cave of the Gorgons they were asleep so he used the winged sandals to fly near Medusa. by using his mirrored shield, he used his sword to cut off her head before she could awake.
On his way back home, Perseus saw Andromeda, a beautiful princess chained to a rock. cassiopeia her mother had offended a sea-goddess so out of revenge Poseidon sent a sea monster to devour everyone in the city unless the king would sacrifice his daughter. peruse killed the sea monster by turning him into stone by using the medusas head.
I will defeat this sea monster.
Perseus and Andromeda sailed back to Seriphus. there, he found his mother imprisoned at the altar where king polydectes had confined her until she agreed to marry him or died of hunger. Perseus went to polydectes place and turned him and his men into stone and then rescued his mother.
Many years later, Perseus was participating in a discus-throwing contest. when he accidentally flung the discus into the crowd and killed a spectator who was Acrisius, his grandfather. the prophecy had been fulfilled; no one can escape fate.