We continue the story about our hero with the myth of Perseus and Medusa the gorgon.
Kind Polydectes sent Perseus to bring him the head of the only mortal gorgon, Medusa. This way, he could remain alone with Danaë and force her to marry him.
Luckily for our hero, goddess Athena decided to help him (she held a grudge against Medusa). She gave him a bronze shield which was polished like a mirror and she told him to look for the Graeae, three of the Phorcydes, who were sisters of the Gorgons and knew their whereabouts. God Hermes helped Perseus, too, by giving him an adamantine sickle.
The Graeae (Enyo, Deino and Pephredo) were three old women who shared one eye and one tooth among them (poor things, they were old ever since they were born). Perseus took their eye when they were passing it from one sister to the other and told them he'd give it back if they told him where he could find the "Nymphs" (in this case, the Hesperides). After they showed him the way, he gave them back the eye and the tooth. (Now this is the part that I couldn't understand: how could they show him the way or take him there, when he had their eye? I couldn't find the explanation in any source.)
A Roman version goes like this: goddess Minerva (Athena) gave him the bronze shield and god Mercurius (Hermes) gave him the winged sandals called talaria, the hat petasus that made him invisible, the sack and the sickle. In this story, the Graeae were the Gorgons' guardians (maybe that's where the expression "to keep an eye on something" comes ;-). Perseus stole their eye and threw it into the lake Tritonis and that's how he got rid of the guardians.
The Hesperides were the nymphs who guarded the orchard were Hera's golden apples were. They were also the keepers of other treasures of the gods. Among these were a sack (called kibisis), a pair of winged sandals and the helmet of Hades, which made invisible whoever would wear it.
Using the winged sandals, Perseus flew to the Okeanos, where the Gorgons lived. Their names were Stheno, Euryale, and Medusa. They had tusks just like boars, their hands were made of bronze and they also had wings made of gold. Whoever looked at them was turned into stone.
Our hero put on the helmet of invisibility and waited until all the Gorgons fell asleep. Then, moving silently with the winged sandals, he went where Medusa slept, looking at her image reflected in the bronze shield. When he beheaded her, the winged horse Pegasus and Chrysaor (who was a normal young man) sprang from her neck (she was pregnant with Poseidon's children).
As you can see, Perseus and Medusa didn't fight directly - he would have had no chance. He managed to do it with the help of the other gods.
As soon as he killed her, he put her head into the sack, without looking at it. Her sister woke up and tried to catch him, but he was invisible and he managed to escape.
In his Metamorphoses, Ovid says that Perseus was tired after the fight and he asked hospitality from the Titan Atlas. He introduced himself, saying he is Jupiter's son, and he promised to tell the titan about his adventures, in exchange for hospitality. But Atlas knew about a prophecy that one of Jupiter's sons will defeat him, so he didn't receive the hero. Perseus was so angry, that he took Medusa's head out of the sack and showed it to Atlas, transforming him into a mountain.
One of the reasons this story could not have happened is the following: Perseus is Herakles' great-grandfather, and we know that Herakles encountered Atlas and they tricked each other into carrying the heaven.
While crossing the desert, drops of Medusa's blood fell on the sand and gave birth to the poisonous vipers of the desert.
For pictures illustrating the story of Perseus and Medusa, click here.
Click here for the first part of the story of Perseus.
Click here for the love story of Perseus and Andromeda.