The Battle of the Labyrinth by Rick Riordan
Rick Riordan twists the plot a bit so that he breaks the predictability factor of the books. This is overall good for the series, as he has only one book to wrap up the story arc after this. Because I am a puzzle-person, the archetype of the maze or labyrinth has always been of interest to me (though please do not put me in one of those panic rooms), so I was probably going to find The Battle of the Labyrinth more interesting by default.
Percy and Annabeth have experienced their fair share of tension, and it escalates with the presence of Rachel Dare, a young human woman who can see through The Mist and understands who Percy truly is. She rescues him from empouli (vampyr-like womanish creatures), and that’s when the next quest emerges. Grover has been tasked to find Pan, the god of the wild, and his credibility and searcher’s license hinges on his ability to do so in the next seven days. Percy must try to find Daedalus in the labyrinth before Kronos-as-Luke does and convince him to join the side of the gods before giving Kronos unimagined powers.
It’s smart of Riordan to break stereotype a bit and to build on his world by fleshing out his present characters and adding in some new ones. Here, Rachel is an excellent foil to both Percy and Annabeth, and she is a worthy sidekick. Grover’s story takes an interesting turn, and the plot itself builds nicely, though not too dramatically, to a conclusion that will set the stage for the showdown at the very end of the series.