Montana, 1876: Gordon Riley's cavalry unit arrives in an alien land to confront an enemy they can't begin to comprehend. Guerrilla fighters strike out of nowhere, then disappear. Civilians are massacred and prisoners are tortured. Contractors are on the take, government agents alter intelligence, and a nation is torn apart as the death toll climbs. Job, Montana, July 1913. When a cruel joke by two young boys forces an old man to confront his dark memories, embittered, aging ex-cavalry officer Riley reluctantly reveals his life story for the first time. And the boys, Billy and Seth, finally discover the truth about the Indian Wars. From the Little Bighorn to the Wounded Knee Massacre, Riley's tale recounts a man trapped in a war he hates, desperate to understand what he's now become. Haunted still by the memories of a lover he could never possess and the battlefield deaths of his only friends, he hides a mysterious bullet marked by a power the Indians called Medicine. The aging cartridge has somehow allowed Riley to survive brushes with death-and now to catch glimpses into the future. Finally, he witnesses a terrifying vision of what the future holds for the two curious boys and must somehow find the courage to intervene on their behalf.