The Tower of Nero
Rick Riordan
The Trials of Apollo (5)
The Mark of Athena
Heroes of Olympus (3)
Trials of Apollo 4: The Tyrant's Tomb
The Trials of Apollo (4)
Trials of Apollo 4.5: Camp Jupiter Classified
Trials of Apollo (4.50)
Thus Spoke Zarathustra
Friedrich Nietzsche