Cajoled into helping an old friend find the cause of her puzzling symptoms, operating room nurse Annie Collins is drawn into a life that has derailed. Libby Mathiesen's doctors and her husband think her symptoms are the result of a miscarriage. Libby is sure they aren't and wants Annie's help to discover what's wrong. Outside her comfort zone and finding Libby difficult to deal with, Annie wonders whether Libby is really ill or if there is more to her story than what she's saying. Annie's need to solve the puzzle drives her to uncover the truth about Libby's illness, but her search for answers doesn't come without a price and threatens her life.