Joan Lowrie and her brutal father, Dan, labor in the English coal mines of the 1870's. Fergus Derrick, a new over-man, attempts to make his workers' lives more bearable but incurs Lowrie's wrath when he fires him for smoking in the mine. Bent on vengeance, Lowrie is beaten when he picks a fight with Fergus, then defiantly smokes in a mine tunnel. There is an explosion, Joan rescues Fergus, and their love triumphs over their class barriers.—AFI