The story takes Jason to the Eastern shore of the Black Sea, in the ancient World the area was called Colchis, which is now Georgia in the Caucasus Mountain region.
Pelias usurps the throne of Thessaly by killing King Aristo; but learns a prophecy that he will be overthrown by a child of Aristo wearing one sandal, and later alienates Hera by killing one of Aristo's daughters despite the goddess' protection. Twenty years later, Jason, Aristo's son grown to manhood, saves Pelias's life during a chance encounter, but loses a sandal doing so, and thus reveals his identity. Upon learning that Jason means to obtain the Golden Fleece, Pelias encourages him, hoping he will be killed in the attempt. Men from all over Greece compete for the honor of joining Jason; men who, because their ship is named the Argo after its builder Argos , are dubbed the Argonauts. Among those chosen are Hercules and Hylas . Acastus, the son of Pelias, is sent by his father to sabotage the voyage. Jason is taken to Mount Olympus by Hermes to speak to the gods Zeus and Hera . Hera tells him that she wishes him well, but adds that he can only invoke her aid five times, and directs him to search for the Fleece in the land of Colchis. On the first occasion of summoning Hera's help, she guides Jason to the Isle of Bronze and warns him to take nothing but provisions; but during a hunt, Hercules steals a brooch pin the size of a javelin from a treasure chamber surmounted by Talos, who attacks the Argo. Jason again turns to Hera, who guides him to open a cylindrical plug on the back of Talos' heel, releasing the latter's vital ichor. Defeated, Talos falls to the ground, killing Hylas; whereupon Hercules refuses to leave until he ascertains the latter's death. The other Argonauts refuse to abandon Hercules, so that Jason calls on Hera again. She confirms that Hylas is dead and that Hercules is not to continue with the others, and directs them to seek the blind soothsayer Phineas, whom they find tormented by two Harpies sent by Zeus to punish him for misusing his gift of prophecy. In return for imprisoning the Harpies, Phineas gives Jason directions and presents him with an amulet. To reach Colchis, they must pass between the Clashing Rocks which destroy any ship that attempts to pass them. When Jason attempts passing through the dark rocks, his ship becomes trapped in the violent sea, and Jason throws Phineas' gift into the water; whereupon Triton holds the rocks in place long enough for the Argo to pass. They pick up three survivors of another ship, among them Medea. At Colchis, Acastus and Jason disagree on how to approach the King of Colchis, and eventually fight. Disarmed, Acastus jumps into the sea to escape. Believing him dead, Jason and his men accept an invitation from King Aeëtes to a feast, where they are captured and imprisoned. Thereafter Medea, enamoured of Jason, helps him and his men escape. Acastus tries to steal the Fleece himself, but is fatally wounded by its guardian Hydra, whom Jason kills to take the Fleece. Aeëtes, in pursuit, sows the Hydra's teeth, producing a skeletal warrior from each. When Medea is wounded in the resulting battle, Jason uses the fleece to heal her, then orders Argonauts to take her to the ship, while he and two of his men fight off the skeletons. When his two companions are slain, Jason escapes to the ship; whereafter he, Medea, and the surviving Argonauts begin the return to Thessaly.