The Lost Hero (Heroes of Olympus) by Rick Riordan

Jason has a problem. He doesn’t remember anything before waking up on a school bus holding hands with a girl. Apparently she’s his girlfriend Piper, his best friend is a kid named Leo, and they’re all students in the Wilderness School, a boarding school for “bad kids.” What he did to end up here, Jason has no idea-except that everything seems very wrong
Piper has a secret. Her father has been missing for three days, and her vivid nightmares reveal that he’s in terrible danger. Now her boyfriend doesn’t recognize her, and when a freak storm and strange creatures attack during a school field trip, she, Jason, and Leo are whisked away to someplace called Camp Half-Blood. What is going on
Leo has a way with tools. His new cabin at Camp Half-Blood is filled with them. Seriously, the place beats Wilderness School hands down, with its weapons training, monsters, and fine-looking girls. What’s troubling is the curse everyone keeps talking about, and that a camper’s gone missing. Weirdest of all, his bunkmates insist they are all-including Leo-related to a “god
Rick Riordan, the best-selling author of the Percy Jackson series, pumps up the action and suspense in “The Lost Hero,” the first book in The Heroes of Olympus series. Fans of demi-gods, prophesies, and quests will be left breathless–and panting for Book Two