When Halt and Crowley discover that the ambitious Morgarath has been infiltrating the Rangers in order to corrupt the Corps, the young Rangers travel north to find Prince Duncan, seeking a royal warrant to stop Morgarath before it is too late. By weakening the Rangers, the most powerful force in support of the King, Morgarath plans to steal the throne.

They have always scared him in the past - the Rangers, with their dark cloaks and shadowy ways. The villagers believe the Rangers practice magic that makes them invisible to ordinary people. And now 15-year-old Will, always small for his age, has been chosen as a Ranger's apprentice. What he doesn't yet realize is that the Rangers are the protectors of the kingdom. Highly trained in the skills of battle and surveillance, they fight the battles before the battles reach the people. And as Will is about to learn, there is a large battle brewing.

They are outcasts. Hal, Stig, and the others - they are the boys the others want no part of. Skandians, as any reader of Ranger's Apprentice could tell you, are known for their size and strength. Not these boys. Yet that doesn't mean they don't have skills. And courage - which they will need every ounce of to do battle at sea against the other bands, the Wolves and the Sharks, in the ultimate race. The icy waters make for a treacherous playing field - especially when not everyone thinks of it as playing.

A kingdom in danger, a great betrayal, a boy seeking to redeem his father's honor. Will he succeed in exonerating him and saving the realm from an enemy in the shadows before it’s too late?

Only Thomas Ward is left. He's the last hope; the last apprentice. Can Thomas succeed? Will he learn the difference between a benign witch and a malevolent one? Does the Spook's warning against girls with pointy shoes include Alice? And what will happen if Thomas accidentally frees Mother Malkin, the most evil witch in the county?