The Sea of Monsters by Rick Riordan
Juvenile: 5th-9th Grade
Magical Adventure Series
The second book in the innovative series Percy Jackson and the Olympians finds many of the same heroes and villains from the first book, The Lightning Thief, back in danger from the monsters that seek out the sons and daughters of the Olympian gods.
For a change, Percy Jackson has nearly made it to the end of a school year without being expelled. The problem with going to school with non-heroes is that, due a phenomenon called "the Mist", they don't see the monsters that come after Percy — they only see the results: broken chairs and windows, burned school buildings, and bruised classmates. When the Laistrygonians, giant cannibal monsters, show up at Percy's laid-back school, the PE coach just sees the big kids taking on the little kids at dodgeball. If it wasn't for Percy giant (if a bit slow) friend Tyson, he would have been killed by the flaming brass cannon-balls tossed in that game.
Annabeth also shows up just in time to slay the last of the cannibals, but she's really come to tell Percy that Camp Half-Blood, the special summer retreat for the scions of Olympus, is under attack again. This time, the magical border that protects the camp is in danger because the tree of Thalia that gives it strength has been poisoned.
Even worse, Chiron is suspected of poisoning the tree, so he has been replaced by a nasty fellow named Tantalus. When Percy realizes that his friend Grover is in trouble, and rescuing him will also allow the tree to be healed, Tantalus awards the quest to Clarisse, the daughter of Ares, who is no friend of Percy's. Annabeth, Percy, and Tyson will need to leave the camp without permission if the quest is to succeed.
Once again, Riordan has crafted a winning story, full of action and witty dialogue. Percy is a nice kid without being a wimp or a wuss, and you want Percy and his friends to succeed, and their opponents to fail. A nice twist is introduced when Luke's father Hermes helps Percy as a way to help his son, even though Luke was hardly helpful to Percy in the first book.
The third book in the trilogy, The Titan's Curse, is out in paperback in April. Definitely worth watching for!