After decades of peace between the white and Native American communities of early American Wyoming, a young man who was once convicted for raping a Cheyenne girl is found dead, prompting sheriff Walt Longmire, his deputy Victoria Moretti, and friend Henry Standing Bear to investigate.

"It's the summer of 1964, and recent college graduates Walt Longmire and Henry Standing Bear read the writing on the wall and enlist to serve in the Vietnam War. As they catch a few final waves in California before reporting for duty, a sudden storm assaults the shores and capsizes a nearby cargo boat. Walt and Henry jump to action, but it's soon revealed by the police who greet them ashore that the sunken boat carried valuable contraband from underground...