Isadora Drey, a citizen of the Alliance, a corrupt, totalitarian state, has been raised to do only one job— train the war horses to be ridden into battle by genetically engineered men, called berserkers. Horse and rider never return from these battles. Unable to face losing another one of her beloved horses, Isadora steals her favorite stallion and flees into a wilderness area, the Boundary. Hunted by government Troopers and rogue berserkers called Blueskins, she falls in with a mute man who seems crazy, yet he holds the key to the survival of the last free living people on the planet. But first he must regain his speech. To do that, he must face the Mirror, an Alliance-made monstrosity designed to kill any human or horse who approaches. Isadora, on her stolen war horse, might help John survive his encounter with the Mirror where everyone else has failed.