Allusions are “textual references to an object or subject that exists outside the text. They use readers’ prior knowledge and associations to enhance emotion or clarify significance” (“Allusion.” SuperSummary). Allusions are one of the most frequently used literary devices in Riordan’s work.

The Camp Half-Blood Chronicles are inspired by Greek mythology. This tradition was established by works such as Homer’s Iliad and Odyssey, Ovid’s Metamorphosis, and Hesiod’s Theogony, among others. Allusions to Greek mythology enrich the content of the novel in myriad ways. For instance, Nico and Will enter the Underworld through the Door of Orpheus. Orpheus was a musician who descended to the Underworld to rescue his wife, Eurydice. The reader who recognizes this allusion knows that Orpheus failed in his mission, which heightens the tension of Nico and Will’s quest for Bob.

The novel’s most obvious allusions are to the demigods’ Olympian parents, which explain how those gods’ natures and powers characterize their demigod children. Apollo, Will’s father, is the god of light, sun, music, poetry, healing and disease, and prophecy. Will inherited powers related to light, the Sun, music, healing, and disease; he laments that he isn’t proficient at archery, another of his father’s skills.