Dangerous to Know — Margaret Yorke

Riding her bicycle about Creddington in her worn sweater and tweed skirt, Hermoine Brown looked as drab, brown, and common as a mouse. Actually she was doing something extraordinary - deceiving her husband, Walter, by secretly taking on two afternoon jobs cleaning houses. For twenty years she had lived in fear of Walter's rages, brutality, and harsh demands. Now, with her daughters grown, she was taking the first small step towards a different life.

Getting away from Walter may be more difficult that Hermoine supposes. Walter has a predilection not only for domestic tyranny, but for women with long, dark hair as well. In fact, Walter Brown has started stalking one such woman he glimpsed on the train home from work.

Of course, no one, not the vicar, the neighbors, the town councilmen, nor Hermoine herself suspect how dangerous Walter is to know. Slowly his obsessions grow. Inexorably, he hatches a new scheme involving the woman on the train, his pathological needs - and his wife.