King Acrisius had a daughter and he was afraid that if the daughter married than the son in law would take over the throne which he didn’t want.
King Acrisius went to an Oracle and a messenger came back to tell him that the daughter would marry and the son would kill you.
King Acrisius locked his daughter in a brass tower that only had a little slit for a window. Over time he thought she would’ve been gone but as he went to the tower in the night and found it glowing and a baby crying. He thought she was protected by the Gods so he sent her far away on the ocean. She landed on an island and raised her baby there which was named Perseus. She always told stories on myths and for a wedding gift for King Polydectes and decided to retrieve the head of Medusa.
Perseus set on a quest and visited the Gary sisters and after some prodding they told him where to find the nymphs of the West. He went to the nymphs of the West and after a promise to come back he had the location of Medusa and he got a cap of darkness, a shield, and a sword. He went to Medusa and cut off her head using the reflection of the shield. He than out the head in a pouch.
Perseus is than chased by Gorgons and he quickly loses them. After spending a night with his cousins like he promised he woke in the morning to a loud thunderous noise. he took medusas head and turned Atlas to stone. Right before he returned home to his kingdom he came along to a girl that was being sacrificed as a punishment for what her mother did. A sea serpent was to kill her. Perseus killed the serpent with his sword and as a reward he was to marry the daughter.
When Perseus finally returned home he found that King was planning to marry his mother. Quickly Perseus told his mother to close her eyes and he brought out Medusa’s head. Everyone in the room including the King turned to stone. Perseus mother told him that her actual father king Polydectes was in the room. Perseus had fulfilled the prophecy and killed his own grandfather but it was still a wedding day since Perseus got to marry the daughter of who he saved.