Rudderless after betrayal by her former fiancé, Montreal heiress Sally Ryder discovers her deceased mother had a secret life and she has a half-sister. Helena has written to Sally, inviting her to Midwinter, an isolated estate in Quebec. But before they can meet, Helena and her husband die under disturbing circumstances.


Sally decides to visit nearby Waverley for a few days nevertheless, to learn what she can about the sister she never knew. Her first shock is to find that her brother-in-law left everything, including Midwinter, to his beautiful secretary Janine. During a storm, Sally is unexpectedly snowed in with  Janine and an assortment of Midwinter guests. It isn't long before Sally becomes entangled with a handsome doctor from Boston in an effort to uncover the truth about her sister's mysterious life, and death.


Meanwhile, the bodies pile up.