Nico begins the summoning ritual. Minos drinks the offering and warns Nico not to trust Percy. When Bianca’s ghost appears, she tells Percy not to feel responsible for her death and tells Nico not to blame Percy either. Bianca hasn’t been answering Nico’s summons hoping that he would give up his mission. She has been secretly Iris messaging Percy so he would stop Nico. Before she vanishes, Bianca tells Nico to give up his dangerous grudge.

That night, Percy has two dreams. In the first, Luke grants Kampe a place in the army so she can get revenge. Then Percy dreams of Daedalus in his workshop becoming annoyed by the boasts of his nephew Perdix. In anger, Daedalus tricks Perdix into tumbling over a balcony to his death, so Athena curses Daedalus for eternity.

The group leaves the ranch, but Nico stays behind with Eurytion. Eurytion gives the group a spider robot to follow to Hephaestus’s forge. Back in the Labyrinth, they encounter a Sphynx. Annabeth volunteers to answer the Sphynx’s riddle, a 20-question trivia test. Annabeth can answer the questions correctly but feels insulted by the lack of challenge. She refuses to continue the test, so the Sphynx attacks.