The third book in the latest series from international bestselling author, Rick Riordan He was a God once. Until he was cast out by his father, Zeus. Now, he's an awkward teenager. Called Lester. The only way out is a series of scary and dangerous trials, of course. For his third trial, Apollo must journey through the Labyrinth to free an Oracle who only speaks in puzzles. Then, defeat the most vicious of three very vicious Roman Emperors.