When Faith Granger's husband Samuel comes back from the First World War he is a changed man. Although still loving to his wife and daughter, Samuel struggles to settle down to normal, civilian life, and Faith seems unable to reignite their old passion. Then Leonie Bonnard, a shy young Frenchwoman, arrives, telling Faith she is a war widow looking for a room to rent for herself and her young child. Faith takes her in, but when Samuel comes face to face with the 'lodger' he realises that his past has caught up with him: he is the father of her child. Leonie threatens to tell Faith everything, and insists that Samuel leave his family for her. How will Faith react when she realises her life has been wrecked by a trusted interloper?