Sometime during the Peloponnesian War Zetes was part of a group of mercenaries, hired by the Cult of Kosmos, who ventured into the Petrified Temple within the Petrified Valley in order to slay the monster therein. The mercenaries initially planned to break into the temple and corner the Writhing Dead but it ambushed them before they got inside. Incapable of forming a strategy, they focused on surviving. A woman delivered the killing blow on the creature, making it drop an artifact. Zetes tried to stop her from touching it but the curse gripped her as she became the next Writhing Dead. Fortunately for him, he was the only one able to escape by using his trusty spear to keep the monster away.
At the height of the war, the misthios Kassandra confronted Zetes asking about the monster. Changed by his experience of seeing "true evil", he recounted his story to Kassandra. After telling her that his spear was what had saved him, she demanded he hand it over. Zetes refused, and they fought, with Kassandra defeating Zetes and taking the spear for herself.
Equipment and skills
Zetes' signature spear, the aptly named Gorgon Slayer, was how he survived his encounter with the Writhing Dread. After that experience, the only way he would let go of the spear was over his dead body. He had sufficient skill with the spear, being able to hold off the Writhing Dread, but he could not hold up to the likes of Kassandra.
- Zetes shares his name with the mythological figure, one of the two sons of Boreas, the Greek god of the north wind. The Boreads Zetes and Calais served as Argonauts, and were pivotal in driving away the harpies that terrorized Phineus of Salmydessus. The brothers were subsequently killed by Herakles out of vengeance for convincing the rest of the Argonauts to leave him behind while he searched for his companion Hylas.