It's the winter of 1884, and five hundred Canadian Pacific Rail workers have halted their push through the Rockies at Holt City, an isolated shantytown in the shadow of the Continental Divide. The men are tired and cold, and patience is as scarce as the rationed food. Then, Deek Penner, a CPR section boss, is brutally murdered at the end of the track. His body is found frozen on the banks of the Bow River.

Durrant Wallace, a veteran of the celebrated March West by the North West Mounted Police a decade earlier, is returned to active duty to investigate the murder. Durrant lost his leg in a gun battle with whiskey traders three years previous, and he struggles with being a Mounted Police officer who cannot ride. When Durrant arrives, Holt City is ripe with possible suspects: illegal whiskey smugglers, spies for rival railways, explosives dealers and a mysterious Member of Parliament who insists on getting his meddling fingers into everybody else's business. Durrant must use his cunning and determination to discover to identify the killer before he finds his next victim and derails the great Canadian national dream in the process.