"King Coal: A Novel" by Upton Sinclair is a socialist novel. Hal Warner, a rich young fellow determined to find the truth for himself about conditions in the mines, runs away from home and adopts the alias "Joe Smith." After being turned away by one coal mine for fear of Hal being a union organizer, he gets a job in another coal mine operated by the General Fuel Company. In the mines he befriends many of the workers and realizes their misery and exploitation at the hands of the bosses. He befriends Mary Burke, who is a passionate fighter for workers' rights. Her father is a mine worker who spends his days drinking and leaving her to take care of her siblings. She and Hal grow close, which tears at Hal's loyalty to his fiancée back home.