Amtrak Wars: Blood River (The Amtrak Wars)

Steve, Cadillac and Clearwater meet with triumph and disaster as they try to evade the clutches of both the Iron Masters and the disguised killer squads sent out by the Lone Star Confederation to purge the overground of renegade Trackers and deserters.
Clearwater's earth-magic gets them out of several tight corners but the Iron Masters prove to be tenacious adversaries and the First Family - the sinister oligarchy who rule the Confederation - have no intention of loosening their grip on Steve Brickman.
Despite his apparent treachery, he is a valuable pawn in a game which, if lost, could spell the end of the First Family's dream of reconquering the blue-sky world.