The Battle of the Labyrinth camp for the school year. On his fifteenth birthday at the summer's end, Percy receives a visit from his father Poseidon, who gives him a sand dollar, admonishing him to “spend it wisely”. Nico later appears to tell Percy his plan to defeat Luke once and for all. "The Battle of the Labyrinth" was initially referred to as "Percy 4" until the title was officially revealed. The novel was teased by Rick Riordan behind the pages of its predecessor, "The Titan's Curse". It was based on the Greek myth of the labyrinth, where the Minotaur was supposedly kept. In his
The Battle of the Labyrinth possessed by Kronos. They run into Grover and Tyson, and discover the resting place of Pan, who speaks to them and passes part of his fading spirit into each. The group, minus Rachel, then heads back to Camp Half-Blood to fight. The Titan army floods out of the Labyrinth and appears to be winning until Daedalus arrives with Mrs. O’Leary and Briares, who kills Kampê. Grover scares off the remaining Titan forces by causing a Panic. After the battle, Nico helps Daedalus to pass on and thus destroy the Labyrinth. After a memorial service for the dead campers, Percy leaves