Percy leaves the Underworld, and he meets the other campers at the Empire State Building. In all, 40 campers have come, excluding Clarisse and the Ares cabin. Chiron puts Percy in charge and says he himself will not be going to Mount Olympus.

The campers enter the Empire State Building, where Mount Olympus is located. They go to the 600th floor, which contains a stone bridge leading to the clouds of Mount Olympus. After walking through the quiet city, the campers enter the palace. Percy sees Hestia, and she shows him a vision. Luke and Thalia are very young, looking tired and hungry in an alley. They encounter a 7-year-old Annabeth who has just run away from home. Luke and Thalia welcome her into their group, and they then travel to May Castellan’s house.  

Percy wakes from the vision, and Hermes, Luke’s father, appears. They explain the issues and try to convince Hermes that Zeus must come to defend the city from Kronos’s attack. Hermes argues with them, saying Typhon is the bigger priority. He gives a message from Athena, Annabeth’s mother. She has said to use plan 23. The campers leave Mount Olympus and look down at the city from an overpass.