Based on the mythological monster whom Herakles slays, Anne Carson's Geryon is a red-winged monster who lives on "an island in the Atlantic called the Red Place" (37). The novel begins during Geryon's childhood and traces his life through his early twenties. A perceptive, curious, and sensitive youth, Geryon carries these traits with him into young adulthood. However, as a child, Geryon's trusting nature gets exploited to the point that he withdraws into himself. He seldom expresses his feelings verbally, cries often, and spends his life hiding his wings under a large coat. Geryon undertakes creating his autobiography in grade school and continues the project until he's forty-four. The project comes to include photography, a medium through which Geryon feels most comfortable interacting with the world around him.

As a boy, Geryon's older brother sexually abuses him without anyone knowing. Though Geryon is close with his mother, he never tells her about the abuse. The abuse kickstarts Geryon's autobiography, but also causes him to "coolly omit all outside things" (29) by withdrawing almost fully into himself. At age fourteen, though, Geryon meets Herakles, a slightly older boy, with whom he engages in a romantic relationship. Though Geryon willingly engages in a sexual relationship with Herakles, he seems to always "have a question about it" (45), which he never feels comfortable articulating to Herakles.