Mostyn Evan and his family, miners turned bargees, wage a glorious but hopeless struggle against rapacious coalmasters, Irish navvies, the ravages of cholera, and the bullying illegal Unions. As they ply their trade between the furnaces of Cyfarthfa and the lush beauty of the Neath Valley, they pray and fight, sing and love, and face each obstacle undaunted with all the stubbornness and exuberance of Wales itself.