Twelve-year-old Percy Jackson is about to be kicked out of boarding school...again. No matter how hard he tries, he can't seem to stay out of trouble. But can he really be expected to stand by and watch while a bully picks on his scrawny best friend? Or not defend himself against his pre-algebra teacher when she turns into a monster and tries to kill him? Of course, no one believes Percy about the monster incident; he's not even sure he believes himself.

Matt is being punished for a crime he saw, but didn't commit. Instead of being locked up, he is being sent to the middle of nowhere to live with a new foster mom, as part of a government scheme called The Leaf Project. But Matt's new home provides anything but peace and quiet. His new guardian is involved in very sinister things, and the whole town seems to be on her side. The truth is much bigger than Matt or the town, but Matt is the only person who can stop the ultimate evil from being unleashed.

Percy Jackson isn't expecting freshman orientation to be any fun. But when a mysterious mortal acquaintance appears on campus, followed by demon cheerleaders, things quickly move from bad to worse.

After a summer spent trying to prevent a catastrophic war among the Greek gods, Percy Jackson finds his seventh-grade school year unnervingly quiet. His biggest problem is dealing with his new friend, Tyson, a six-foot-three, mentally challenged homeless kid who follows Percy everywhere, making it hard for Percy to have any "normal" friends.