Kidnapped on his way to boarding school, Danny Caulfield, who has one blue eye and one brown eye, ends up at a mysterious academy of spies, where he is to be trained in the art of espionage in an effort to keep the Upper and Lower worlds from colliding.

The nefarious leader of the Ring of Five, Ambrose Longford, is still determined to control both the Upper World and Lower World. But Danny and his friends at Wilson's school for spies stand in his way. As Danny struggles with his role in the spy world, Longford is attempting to bring down the other members of the Ring, to usurp all of its power. Or is he?
In this exhilarating conclusion to the Ring of Five trilogy, Eoin McNamee's twists and turns...