In Pontypridd and the Rhondda in 1905 coal is king and the families who sunk the first collieries are rich. None is wealthier or more generous a benefactor than Harry Watkin Jones.

At 20, Sali Watkin Jones is about to marry her childhood sweetheart, Mansel, a young and successful businessman, in Pontypridd's wedding of the year.

But as tragedy follows tragedy, four short and traumatic years later Sali becomes a penniless outcast fleeing from a violent husband and struggling to support herself and her son in a world very different to the one in which she has been brought up. Sali finds work in the home of family of colliers. Here she and her son find the warmth and love missing from their lives for so long.

As the miners' wages are eroded by the greed of the companies who have replaced the private owners, unrest and violence come to the valleys.