Telegonus plays a significant role in Circe, but he does not appear in the text of the Odyssey itself. The mythical figure of Telegonus is the son of Circe and Odysseus. According to some ancient texts, Telegonus is sent to Ithaka to find his father. While there he mistakenly kills Odysseus and absconds with Penelope and Telemachus back to the island of Circe.
Although Homer does not mention him, Telegonus does appear in several other classical sources. Much of the story of Telegonus as it has been adapted in Circe comes from the poem Telgony by Eugammo of Cyrene. Almost all of this 7th Century BCE cyclic poem has been lost. It may have been part of a larger series based on Homer's epics. Although nearly all of the original work has been lost to time, a 2nd Century CE collection contains a summarized description of the original poem. There are also several brief accounts of the story of Telegonus in works by the Roman writers Hyginus, Horace, and Ovid.
When writing Circe, Madeline Miller drew much of her inspiration from Homer's epic works themselves. However, in order to create a more colorful and in-depth story about her title character, Miller went beyond the more familiar works of Homer and utilized much more obscure ancient sources.