Percy, Leo, and Nico head to a wizarding school called Hogwarts to bring a demigod to camp before monsters attack the wizarding world. While they track down this demigod, they must also look for Annabeth, who has been kidnapped, and is thought to be inside Hogwarts. They are slowed, however, by a trio who are suspicious of them, and are getting close to finding out their secret.
I give all credit to J.K. Rowling and Rick Riordan. The characters in this book are theirs not mine.