Luke Sheldon is a diabetic fifteen year old from London. With an elder brother (who constantly bullies him) about to go to university, Luke can't wait to get the room they share all to himself. One morning, he receives a letter from the WRYP (Well Rounded Youth Project) – a camp for smart children – telling him he's been invited to a camp in the USA.
When he gets to Heathrow Airport to meet the leaders and fellow campers, he spots his best friend from his old school, Natalie Anderson – a girl as smart as he is. The two of them make friends with another boy – Matt Newbury. After a plane ride to New York, the campers take a bus to the Adirondack Mountains – the home of Camp Hope.
After settling in and meeting his camp councilor, Drew, the fun of the camp starts with hiking, horse-riding and archery. After lunch, Luke finds a coded message in his cabin. Later on, Luke and his friends assemble to decipher the code; they reveal a message about a treasure quest. But when further clues arrive, the hunt leads Luke into the forbidden tunnels in the surrounding forest. When things begin to go wrong, he realizes his taste for problem solving has lead him to bite off more than he can imagine.