The novel’s most overt allusion to other literature is the Eurydice Candle, which takes its name from the story of Eurydice and Orpheus in Greek mythology. According to Ovid’s Metamorphoses, Eurydice marries Orpheus but is killed by a snakebite shortly after their wedding. Grief-stricken, Orpheus journeys to the underworld to recover his bride. Hades agrees to let Eurydice return to the mortal world on the condition that Orpheus resist the temptation to look back at her as she walks behind him. Once Orpheus reaches the surface, he looks back, but Eurydice has not yet fully emerged from the gateway. She is pulled back into the underworld.

In The Ex Hex, the Eurydice Candle is used to contain a spirit so it can be released later in a different location. While its name refers to Orpheus’s attempt to relocate Eurydice’s spirit, the candle’s deeper significance becomes clear as Vivi and Rhys navigate their own trust issues. Thomas Bullfinch wrote that Orpheus did not trust that Eurydice was with him—either she was real and did not follow, or she was an illusory trick by Hades—and for his distrust, Eurydice died twice. In The Ex Hex, Vivi mistrusts Rhys because of his rakish attitude.