Percy visits Mrs. O’Leary, “the world’s only friendly hellhound” (79), in the camp arena. She runs off into the woods, and Percy follows her to find three individuals gathered together: Nico di Angelo, Juniper, a tree nymph, and Leneus, an old satyr. They are arguing about Grover Underwood, a satyr who has been missing from camp for the past two months. Juniper, Grover’s girlfriend, insists that he should be contacted and brought back so that he can help fight against Kronos. Both Nico and Leneus deny knowledge of his whereabouts.

Juniper and Leneus depart, and Nico reveals that he has been speaking to Charles’s ghost, who now resides in Elysium. Nico also reveals that he was spying on the Titans just as Percy saw in his dream in Chapter 1. In order to defeat Kronos, Nico has a plan to make Percy “invincible” (87). The reader later learns that this ultimately entails Percy bathing in the River Styx, which will make him powerful and invulnerable to his enemies. However, the first step is to learn more about Luke’s childhood and visit his mother in Westport, Connecticut. Percy rides Mrs. O’Leary to Westport, and they use “shadow travel” (89).