By good fortune, when Perseus arrived where the Gorgons resided they were all asleep, Persues took aim and sliced Medusa's head off. The other Gorgons awoke but Perseus flew away with the cape of darkness and they could not find him.
On his way back home he stopped by Ethiopia, a girl named Andromeda was to be devoured by a sea monster because her mother had boasted that she was more beautiful that the daughters of the sea god. Perseus saw Andromeda and instantly loved her. He waited for the great sea monster to come and cut its head off
He took Andromeda and they sailed back to the island and his mother. Once he arrived he found nobody in the home.
Danae and Dictys had to hide themselves from the wrath of Polydectes, who was furious at the refusal of Danae to marry him. They had taken refuge in a temple.
Perseus learned that the king was holding a banquet and saw his opportunity to kill him. He took the head of Medusa, walked in, and turned the cruel king and his courtiers to stone. He then was reunited with Danae and Dictys.
Perseus would make Dictys the new king as he and his mother decided to go back to Greece and find Acrisius. He wasn't there but it so happens that upon their arrival Persues heard of an Athletic contest being held. He participated and threw a disc which struck a bystander and killed him. That bystander was Acrisius. So the prophecy reigned true.