Jason and the Argonauts' quest for the Golden Fleece, in the only complete epic account of the myth to survive from antiquity.
Apollonius of Rhodes wrote the Argonautica in the 3rd century BCE, working at the great Library of Alexandria, and it stands as the only complete surviving epic telling of Jason's voyage aboard the Argo in search of the Golden Fleece -- alongside Medea, whose portrayal here as a young woman falling into a destructive love shaped how later writers, including Virgil for Dido, would handle women driven to extremity by passion. Where Homer's epics feel like the product of a long oral tradition, Apollonius was a self-consciously literary poet writing in a library, and the Argonautica shows it: dense with geography, myth, and scholarly allusion in a way that rewards careful reading over the propulsive momentum of the Iliad or Odyssey.