From the time Louise Vickers arrives at the shadowy old country house, she notices a change in her secretary. Harriet is rude and antagonistic to all the people in the house, particularly Elizabeth Byron, the owner. Louise discovers that Harriet was once engaged to Tom Byron, Elizabeth's alcoholic brother.

Harriet is stabbed to death and the rich elderly invalid upstairs dies of fright. Was there something else in Harriet's past life, or had she stumbled on some secret involving the prospective heirs? Why was Martha pretending to be a servant when she obviously wasn't? Why did the young musician drug the trained nurse? And what of Corinne, recently recovered from a nervous breakdown who now walks in her sleep? And wasn't Mrs. Smythe, the sweet and gentle bore, just a little too good to be true?

Slowly but surely the author unfolds this psychological thriller and arrives at a startling denouement.