Perseus is about to fight medusa while Athena is giving him advice and guidence to make sure that perseus will win the battle and get to back to his home and make sure Perseus's mom doesen't marry the chief.
Perseus is about to take the head of medusa and is about to take her head to finish his final quest. He cuts her head off to take his mother back from the chief.
Perseus has the head and is taking it back to his home to give it to polydectys. He is bringing it back to polydectes so that he can gain his mother back and save his wife so he can leave the island.
Perseus was heading back to town when Hermes checked up on him. He was making sure he successfully finished his task on getting Medusa the Gorgon's head.
Polydectes is surprised on how he is actually presented thehead. He gives back his mom and wife. He dies and Dectys becoming the king of the island and they all leave, to a different island. Which also happens to be the island that his mother, Danae came from.
After the journey, Perseus went to Argos with his mother and heard how a neghboring city was holding games. Fortunately Danae's father was actually there and was watching from a distance. Perseus was playing discus and killed the king. Thus, the prophecy of Delphi was fulfilled.