From Wikipedia

The Battle of the Labyrinth is a 2008 fantasy-adventure novel based on Greek mythology; it is the fourth novel in the Percy Jackson & the Olympians series by Rick Riordan. Fictional demigod Percy Jackson—who is fifteen years old by the end of the book—tries to stop Luke Castellan and his army from invading Camp Half-Blood by navigating Daedalus's labyrinth. It was released on May 6, 2008 in the US and Canada. It was received positively overall, with the novel being a #1 The New York Times children's series best seller and a #1 chapter book bestseller. Read more - Shopping-Enabled Wikipedia on Amazon

      In the article: Synopsis | Critical reception | Audiobook | Sequel

From School Library Journal

Grade 5–9—The battle starts, literally, with an explosion and doesn't let up. After Percy destroys the high school band room battling monsters called empousai who have taken on the form of cheerleaders, he has to hide out at Camp Half-Blood. There, Grover's searcher's license is going to be revoked unless he can find the god Pan in seven days. An entrance to the Labyrinth has been discovered, which means that Luke, the half-blood turned bad, can bypass the magical protections and invade the camp. Annabeth insists that she must follow a quest to locate Daedalus's workshop before Luke does. Percy is disturbed by visions of Nico, the son of Hades, who is summoning forth the spirits of the dead with McDonalds Happy Meals. Percy, Grover, and Percy's Cyclops half-brother follow Annabeth into the maze not knowing if they will ever find their way out. Riordan cleverly personifies the Labyrinth as a sort of living organism that changes at will, and that traverses the whole of the United States. Kids will devour Riordan's subtle satire of their world, such as a Sphinx in the Labyrinth whose questions hilariously parody standardized testing. The secret of Pan is revealed with a bittersweet outcome that also sends an eco-friendly message. Like many series, the "Percy Jackson" books are beginning to show the strain of familiarity and repetition. However, the overarching story line remains compelling, and the cliff-hanger ending will leave readers breathless in anticipation of the fifth and final volume.—Tim Wadham, Maricopa County Library District, Phoenix, AZ
Copyright © Reed Business Information, a division of Reed Elsevier Inc. All rights reserved.