A half-hour before midnight on June 8, 1917, a fire broke out in the North Butte Mining Company's Granite Mountain shaft. Within an hour, more than 400 miners were trapped 2,000 feet underground, and many would not survive. Here the author of the novel The Revenant recounts the remarkable stories of both the men below ground and their families above, but also that of Butte, Montana, a volatile jumble of antiwar protest, seething labor unrest, and radicalism both left and right. It was a powder keg lacking only a spark, and as Michael Punke explains, the mine fire would ignite strikes, murder, occupation by federal troops, and ultimately a battle over presidential power.