Twenty miles east of Devils Tower, in the sleepy town of Cascade, Wyoming, a cryptic letter is found. It mentions a "wealth of a nation," and reads as nothing more than fanciful fiction, except that its author was one of the most influential men in American history, famed explorer and former President of the United States, Theodore Roosevelt. The letter also references the Seven Sisters of Native American folklore. The correlation between the two subjects is unknown, even to Chatan, the message's discoverer, a young man with Lakota ancestry. Unsure of who to trust, he contacts his uncle, Yellowstone park ranger Tatanka "Bull" Durham. Suspecting trouble, Bull asks his friend and trusted coworker, former Delta operator Jack Reilly, to come along. Seeing it as a way to square up a dangerous debt, shady casino owner Bartholomew Creed swiftly takes matters into his own hands. The potential dollar amounts involved are too great not to act. But is it enough to kill for?