Orphaned and abused, Isadora has been raised by the Alliance to do one job - train the war stallions to be dangerous weapons to be ridden into battle by enhanced men called berserkers. Desperate to not lose another of her beloved horses, Is steals her favorite stallion and escapes into the Boundary. Hunted by government troops, rogue berserkers and other outlaws, Is falls in with a mute, mad stranger. Though John's unpredictable behavior frightens Is, she may be the only one who can help him survive his courageous quest to overthrow the Alliance and ensure the survival of the last free-living people on the planet.