The Hidden Oracle
Rick Riordan
The Trials of Apollo (1)
Keeper of the Lost Cities
Shannon Messenger
Keeper of the Lost Cities (1)
How to Be a Pirate
Cressida Cowell
How to Train Your Dragon (2)
The Battle of the Labyrinth
Percy Jackson and the Olympians (4)
Hero's Guide to Deadly Dragons
How to Train Your Dragon (6)