Percy, Annabeth, Rachel, and Nico leap from Daedalus’s workshop using bronze wings. Percy panics at first, but Annabeth tells him how to glide, and the group lands safely at the Garden of the Gods visitor centre before the wings fall apart. Daedalus’s workshop vanishes from the hillside, and Nico senses that Daedalus is not dead, meaning the Labyrinth may still exist.

Annabeth decides they must re-enter the Labyrinth and return to Camp Half-Blood before Luke’s army can invade. Rachel secures a chauffeured car by invoking her identity as Miss Dare, though Percy does not understand her influence. After Annabeth contacts Chiron and learns the camp is preparing for battle, Rachel guides the group through Colorado Springs and finds a boarded-up mine entrance marked by Daedalus’s symbol.

Back inside the Labyrinth, Rachel easily leads the way toward New York. Annabeth and Rachel unexpectedly bond over architecture, while Percy speaks with Nico about Daedalus, Bianca, and Nico’s isolation among the dead. At a crossroads, Rachel senses a dangerous tunnel, Nico smells death, and Percy recognizes the eucalyptus scent of Mount Tamalpais, realizing the tunnel likely leads to Luke’s entrance to Mount Othrys.

Percy borrows Annabeth’s invisibility cap and scouts the tunnel alone. On Mount Tam, Percy sees telekhines and Ethan Nakamura preparing Kronos’s reforged scythe, Backbiter, and then slips into the black fortress. Inside, Percy opens the golden sarcophagus of Kronos and finds Luke’s seemingly dead body, with a wound where his heart should be.

The telekhines arrive with Ethan, and Percy reveals himself to stop Ethan from swearing loyalty to Kronos. Ethan admits that he is a son of Nemesis and believes revenge against the gods is his purpose, so Ethan renounces the gods and pledges himself to Kronos. Ethan’s oath revives Kronos inside Luke’s body, restoring Luke’s wound and giving the Titan golden eyes and command of the scythe.

Percy attacks, but Kronos easily deflects Riptide and bends time to trap Percy as Percy tries to flee. Rachel, Annabeth, and Nico arrive, and Rachel frees Percy by hitting Kronos in the eye with a hairbrush. Nico raises a massive rock spire that damages the fortress entrance, delaying Kronos and the telekhines long enough for the group to escape back into the Labyrinth.