The three main characters, Jason, Leo, and Piper are on a field trip, to the grand canyon. They are there for a while, but then a huge storm pops out of nowhere. Its not actually a storm, but it is the storm spirits going after Jason, Leo, and Piper. The storm spirits knock Piper into the Grand Canyon and Jason goes in after her.
Jason, Leo, and Piper have arrived at camp Half-Blood. They are flown in by a magical chariot with gods in them that arrived at the Grand Canyon. They are first taken to this building where gods will claim them as either a son or a daughter of this god and that one. After that, They are taken to camp Half-Blood.
Jason, Leo, and Piper are on Festus, thier dragon. They are on a quest to stop an evil god trying to destroy the god Geae.