The fourth and quite possibly most dangerous novel in the series yet.  The Battle of the Labyrinth takes Percy from another new school, which he may or may not have played a part in blowing up, to the labyrinth underground.  Cronus is summoning an army and his eyes are set on destroying Olympus but in his way is Camp halfblood and the heroes of Olympus.  Seeking to find a way to swiftly move his army across the country Cronus has sent scouts into the labyrinth to find a way through or to find it’s creator Daedalus.  As the minor gods determine their allegiance Percy, Annabeth, Grover, and Tyson must quest to find Daedalus and win him over to the Olympians cause.  This book sets up the series finale in which Cronus will rise to either destroy Olympus or fail in his conquest.

Battle of the Labyrinth is a great inclusion to the series with plenty of action and adventure.  Quick paced, this is a great book for boys and reluctant readers.  Grades 5-8.