Huw Morgan, the academically-inclined youngest son in a proud family of Welsh coal miners, witnesses the tumultuous events of his young life during a period of rapid social change. At the dawn of the 20th century, a miners' strike divides the Morgans: the sons demand improvements, and the father doesn't want to rock the boat. Meanwhile, Huw's eldest sister, Angharad, pines for the new village preacher, Mr Gruffydd.