The lost Hero is a book in a series called the heros of olympus. It is about the proficy of 7 thet ended the percy Jackson books.
To undestand it you have to read the Percy Jackson books.
9781423113393The book starts off where a guy named Jason wakes up on a bus to a school he cant remember a thing. Piper is a girl who has a relation ship with jason but jason does not remember so now piper is woried that the whole thing was just a dream. Last we have leo who somtimes feels a little left out because piper and jason have a relation ship with eachothe. Then a little bit later some people wisk them to a place called camp half blood. Where Annabeth is trying so hard to find percy.