When Captain Merrivale dies, his daughters Martha and Penelope are left almost penniless. They find employment as schoolteachers in the Lancashire mill-town of Tapton working for mill-owner Jonas Wright, charged with educating not only his own four young daughters, but also some of the more promising mill-workers. On arrival at Tapton they find more than they had bargained for. Penelope is caught up in a riot which brings her into contact with a disgruntied worker, Clem Porter, a man whose family have been brought close to starvation by a rival mill-owner's ill-treatment. Meanwhile Martha finds herself drawn, against her better judgement, to Ben Seaton, the father of one of her charges. She is as angry at this disruption to her plans to remain a spinster as he is to find himself attracted to such a demanding and seemingly stern young woman...