When Perseus pushed his way through the forest, where he was told Medusa was, he used his shield to guide his way and when he did, he found a graveyard of her previous victims, and then her.
Perseus used his shield’s reflection to guide his sword, and when he found the right angle, he cut through all the snakes until he cut her head off.
After Perseus beheaded Medusa, Chrysaor and Pegasus came out of her womb, as she was unable to give birth to them while she was a monster. They saw what Perseus did and tried to kill him, however Perseus had the Hermes’ shoes, that flew across the sky and lost trace of the two.
On his journey home he found a woman and man in front of a crowd on shore of an island. Perseus also saw a monster in the sea, however it was a ways away from them. When he came to the ground he questioned the king and realized that it was a sacrifice. He greatly opposed this, so he killed the monster and took the woman to be his bride.
When he came back to Sephiros, he was surprised to find no one there. But when he went into the castle he realized that everyone was fighting, he found that Polydectes who was trying to marry his mother. He took the head out of his bag and turned everyone except his mother to stone. The prophecy was correct, he turned his grandfather to stone.