The Tower of Nero is the fifth and final volume in the Trials of Apollo series by Rick Riordan, concluding the adventures of Apollo who was cast down into human form by Zeus and who has spent the previous four books trying to regain his place as the god Apollo.  The previous titles are The Hidden Oracle, The Dark Prophecy, The Burning Maze, and The Tyrant’s Tomb.  We have all five books in the Children’s and Young Adult fiction collections.