Perch of the Devil by Gertrude Atherton — Read

Two weeks later Ora and Ida sailed from Havre. Gregory had cabled, and the _Herald_ had published a dramatic account, of the wounding of Mr. Mark Blake in the tunnel of his wife's mine. The engineers' lease had expired and he had closed down the mine temporarily. The sinking of the inclined shaft in the "Apex" had proceeded very slowly owing to the uncommon hardness of the rock; it would seem that Nature herself had taken a hand in the great fight and enlisted for once on the side of the weaker power. Although when Osborne and Douglas had turned over the mine, their cross-cut almost had reached the point on the vein which the new shaft expected to strike, Gregory had risen twice in the night and walked along the hill beyond his boundary, reasonably sure that all the blasting was not in the shaft, his keen ear detecting muffled reverberations slightly to the east and at a greater depth.

He communicated his suspicions to Mark, and on the following night they examined the lock on the Primo shaft house and discovered that it had been tampered with. They went down by way of the ladder; and in the cross-cut on the chalcopyrite vein they found miners working with hand drills. There was a desperate hand-to-hand fight with the manager and shift boss; the miners, who were bohunks, proceeding phlegmatically with their work.