Percy Jackson''s fourth summer at Camp Half-Blood is much like his previous three-high-octane clashes with dark forces, laced with hip humor and drama. Opening with a line for the ages-"The last thing I wanted to do on my summer break was blow up another school"-this penultimate series installment finds Percy, Annabeth and the satyr Grover furiously working to prevent former camp counselor Luke from resurrecting the Titan lord Kronos, whose goal is to overthrow the gods. When the heroes learn that Luke can breach Camp Half-Blood''s security through an exit from Daedalus''s Labyrinth, they enter the maze in search of the inventor and a way to stop the invasion. Along the way they encounter a lifetime supply of nightmare-inducing, richly imagined monsters. Grover''s own quest to find the lost god Pan, meanwhile, provides a subtle environmental message. Percy, nearly 15, has girl trouble, having become something of a chick magnet. One of Riordan''s strengths is the wry interplay between the real and the surreal. When the heroes find Hephaestus, for instance, he''s repairing a Toyota, wearing overalls with his name embroidered over the chest pocket. The wit, rousing swordplay and breakneck pace will once again keep kids hooked.-PW