Book 1 in the New York Times bestselling series, soon to be a TV show on Disney+! 'This book reminded me of some of the children’s books I grew up with, like Charlie and the Chocolate Factory and The Phantom Tollbooth.' RICK RIORDAN, author of the PERCY JACKSON series 'Like the Potter books, this story goes beyond mere adventure' BOOKLISTWhen a peculiar advertisement appears in the newspaper for children to take part in a secret mission, children everywhere sit a series of mysterious tests. In the end, just four children succeed: Reynie, Kate, Sticky and Constance. They have three things in common: they are all honest, all remarkably talented and all orphans. They must go undercover at the Learning Institute for the Very Enlightened where the only rule is that there are no rules. There they must work as a team to save not only themselves, but also the world outside the walls ... Book 1 in the 4-book New York Times bestselling adventure series – ideal for children aged 10 and up Join a group of smart and resourceful junior sleuths as they solve a series of page-turning puzzles and mysteries Perfect for fans of Robin Stevens's MURDER MOST UNLADYLIKE series The adventure continues in book 2, THE MYSTERIOUS BENEDICT SOCIETY AND THE PERILOUS JOURNEY