On June 8, 1917, deep beneath Butte, Montana, a small flame touched the wrong material and turned one of America's richest copper mines into a killing chamber. In minutes, smoke and poisonous gas were racing through the Granite Mountain-Speculator workings, swallowing drifts, ladders, and men who knew the dark by heart. Some ran. Some hid. Some sealed themselves behind doors and prayed the air would hold. For 163 miners, it did not. The Speculator Mine plunges you into the last ordinary shift before catastrophe and follows the disaster as it unfolds in real time: the crew at the shaft, the men groping through blackened tunnels, the rescuers descending into a mine still thick with poison, and the families aboveground waiting for names. As the dead are counted, the story widens into a battle over blame, safety, and power in a city where copper fed a nation at war and profits depended on men going back underground. Written with narrative force and grounded in the historical record, this is a scrupulous, character-driven account of one of the deadliest hard-rock mining disasters in American history-and of the labor uprising it helped ignite. The fire ended in 1917. Its questions never did.