King Polydectes speaks about how he wants the head of Medusa as a wedding gift, and Perseus takes it upon himself to go fetch it for the king.
In this story, Perseus is aided by both the goddess Athena, and Nymphai. Athena gives Perseus the advice on how to kill Medusa, and also gifts him the shield and sword to do so. The Nymphai provide Perseus with Hermes sandles, a helmet of invisibility, and the kibisis.
Reward and Journey Home
Perseus's tests in the story are to find where the Nymphai are located, and he has to blackmail the Graeae, and after this he has to head to the cave to fight the gorgons and slay Medusa.
The supreme ordeal of this story is in fact, Medusa. Perseus finds Medusa sleeping in the cave. He cuts her head off, and narrowly escapes using the helmet of invisibility.
Perseus flies back home with Medusas head snug in his kibisis. Upon arrival he earns princess Andromedas hand in marriage as his reward.
The king is still trying to force Danaes hand in marriage, but Perseus fights him and uses Medusas cut off head to turn him into stone. Now everything is fine again