When Perseus arrived at the country of the Hyperboreans the gave him winged sandals,magic wallet,a cap which could make him invisible.When he got these he flew across over the sea to the Terrible Sisters island.
When he arrived they were all asleep,Athena told him which one was Medusa,the other two were immortal.He then flew over and with a single sweep he cut through her neck ,put her head in the wallet.
On his way back he came to Ethiopia and found out that a maiden had been given up to a sea serpent.Her name was Andromeda,when he came he waited until the serpent came for her and then cut its head off.
When Perseus slayed the monster he took Andormeda to her parents and asked for her hand,which they gladly gave him.
When arrived back on the island he found his mother and Dictys taking refuge in a temple,since Danea refused to marry Polydectes.Polydectes was having a banquet and Perseus saw his opportunity ,when arrived he pulled Medusa's head out Polydectes and everyone else turned to stone.
After Polydectes turned to stone Dictys became the king of the island.Perseus and his mother went with Andromeda to Greece,where Perseus and Andromeda had a son named Electryon.