This is the fourth book in the Percy Jackson series, rather blatant Harry Potter clones, only Percy is a demigod, not a wizard. Only to be fair, the series has been developing its own personality as we go along, and Riordan's writing has been getting stronger. This is actually the second book in a row where I haven't constantly been thinking of Harry Potter, especially since we've gained some strong guest stars--Zoe Nightshade in The Titan's Curse and Quintius in Battle of the Labyrinth. And I do enjoy the whimsy with which Riordan mixes classical myth with Americana. I mean how cool, how perfect is it that Harriet Tubman was a daughter of Hermes? And we finally get an explanation here for how Annabeth can be a daughter of Athena, one of the maiden goddesses--and it's clever. Being no environmentalist, I could have done without the kumbaya Green moment with the developers-are-evil riff--even if I did like the message that the fate of the world is in our hands, not that of the gods. I liked this only a little less than the last book, but it's better than the first two certainly and had me quickly leaping to the next--and alas last--book.