The Battle of the Labyrinth
Rick Riordan
Percy Jackson and the Olympians (4)
The Lost Hero
The Heroes of Olympus (1)
The Son of Neptune
The Heroes of Olympus (2)
The House of Hades
The Heroes of Olympus (4)
The Blood of Olympus
The Heroes of Olympus (5)
The Hidden Oracle
Trials of Apollo (1)
The Dark Prophecy
Trials of Apollo (2)
The Burning Maze
Trials of Apollo (3)