An escaped military-grade human experiment, Nox is running from men determined to keep him a secret. Critically wounded and loosing fuel, he makes one last, desperate move, and crashes into Cress Montgomercy's farm truck. Cress has her own mountains to climb trying to keep her family together, and at first she thinks having a Mech around might save the farm - until the men who are hunting him show up. In the life-or-death race that follows, Cress, her brothers, and Nox must learn to trust each other if they are going to survive the brutal journey over the mountains to the protection of the rebel forces on the border of the Coalition Colonial Region. But with the threat of war blossoming in the Colonies behind them, mercenaries on their trail, and an uncertain future in the rugged Illyrian settlements ahead of them, will they find safety, or will they be swept up by the battle Nox was designed for?