The Hero's Journey is a framework that scholar Joseph Campbell came up with that many myths and stories follow. Many storytellers and story-readers find it a useful way to look at tale. (That's actually putting it lightly. Some people are straight-up obsessed.) Chris Vogler adapted Campbell's 17 stages of a hero's journey, which many screenwriters use while making movies. Vogler condensed Campbell's 17 stages down to 12, which is what we're using. To read a general explanation of the 12 stages, click here.
Perseus' story doesn't fit perfectly into the Hero's Journey structure, but we're giving it a shot. As the gross old saying goes, there's more than one way to skin a cat. Here's how we've diced up the story:
We start the story on the island of Seriphus, the home of Perseus and his pretty mother Danae. Though Perseus doesn't know it yet, Polydectes, the king of Seriphus, has the hots for Danae, but he needs to get Perseus out of the way before he can marry her.
King Polydectes orders Perseus to bring back the head of Medusa. (That sounds like a pretty effective way to get Perseus out of the way – permanently.) Perseus accepts the challenge even though it seems like an impossible task.
There's no refusal in this story. Though he might be inwardly freaking out a bit, Perseus hops to it.
Athena and Hermes guide Perseus to the home of the Graeae and give the guy some advice.
Perseus really commits to his adventure when he blackmails the Graeae into telling him how to find the Nymphai. At this point, he has entered the mythological world of strange creatures and gods.
Perseus' main test is finding out the location of the Nymphai. To do this, he has to trick and blackmail the Graeae, which he successfully does.
Next, Perseus gains two important allies. First of all, the Nymphai loan Perseus lots of useful stuff, like Hermes' winged sandals, Hades' helmet of invisibility, and the kibisis. Second, Athena offers Perseus some great advice about how to defeat Medusa (only look at the monster through the refection on your shield). Good thing Perseus has some friends.
With his borrowed magical gear, Perseus flies off to find the Gorgons' cave. The Gorgons will certainly be his enemies.
How convenient – the Gorgons actually live in a cave. When Perseus reaches the Gorgons' lair, he's about to embark on the most dangerous part of his adventure.
Perseus finds Medusa sleeping and chops off her head. The other two Gorgons chase him, but Perseus escapes with the help of Hades' helmet of invisibility (a.k.a. Helm of Darkness).
Perseus has got Medusa's head, which is certainly a kind of reward. While flying home to Seriphus, though, he also wins Princess Andromeda's hand in marriage.
Perseus flies back home with Medusa's head packed away in his kibisis.
This stage has a kind of funny name, because it isn't necessarily about death and resurrection: "This is the climax in which the Hero must have his final and most dangerous encounter with death. The final battle also represents something far greater than the Hero's own existence with its outcome having far-reaching consequences to his Ordinary World and the lives of those he left behind" (source).
What's at stake for Perseus is his mom's freedom. Perseus' last battle is with King Polydectes, who has be trying to force Danae to marry him. Perseus takes care of Polydectes by using Medusa's head to turn him into stone.
Perseus has returned home and saved his mom. His quest is over. He came home with the cure to his mom's desperate situation, and now he returns his magical artifacts to the Nymphai and gives Medusa's head to Athena.