The House of Hades
Rick Riordan
The Heroes of Olympus (4)
The Lost Hero
The Heroes of Olympus (1)
The Mark of Athena
The Heroes of Olympus (3)
The Son of Neptune
The Heroes of Olympus (2)
The Burning Maze
Trials of Apollo (3)
The Dark Prophecy
Trials of Apollo (2)
The Hidden Oracle
Trials of Apollo (1)