Lucinda "Lu" Calder is an experienced miner, sent to investigate possible irregularities at Brushy #3, a coal mine owned by her step-father, in eastern Kentucky. Acting as a transfer from another mine in the West, she is hired as a general miner and mechanic. As the first, and only, female miner at Brushy #3, she puts up with some distrust and hazing from her male counterparts to test her mettle.
One of the first people she meets is an attractive woman in personnel named Regina Kinlaw. Regina is the single mother of a nine-year-old daughter, who is relentlessly curious. When Regina's van breaks down, Lu stops to assist and is drawn to the young woman. Even though Regina seems stand-offish and secretive, something about her intrigues Lu. But she has a job to do and can't allow herself to be distracted by wishful thinking.
The area surrounding Brushy #3 is a close knit, rural community and Lu finds herself thrown into situations that bring her into more frequent contact with Regina than she planned. They also bring her into contact with a man who believes Regina is his future wife and resents the time Regina spends with Lu. It's a situation that jeopardizes Lu's mission, and eventually her life.