Perseus was at first afraid of the island of the Gorgons because he saw all the people that had turned to stone. He then approached Medusa while she was asleep. With one swift blow he was able to cut off Medusa's head.
The Road Back
When Perseus began to fly away with Medusa's head the other two Gorgons woke up. The Gorgons became pursuers as they chased Perseus. Perseus got away though because he had the cap of invisibility on and couldn't be seen.
Perseus now had a new found confidence since he completed his mission. He also had the three gifts from the nymphs of the North and Medusa's head. He now went home flying with his winged sandals.
Return with the Elixir
On Perseus' way back home he noticed a dangerous sea creature. This sea creature was about to devour a lovely princess, Andromeda. Perseus slew the creature and saved Andromeda, who promised to become his wife.
Polydectes had doubted that Perseus had achieved his goal. Perseus then grew angry when he realized that the king just wanted to get rid of him. To prove what he had done Perseus pulled out the Medusa head turning Polydectes to stone.
Perseus had killed the cruel king so now the kind Dictys could then rule. Also Perseus now had a new wife, Andromeda. He now felt accomplished with all that he had done.