Arriving home from a party, Margaret and Stephen Frawley discover that their children, three-year-old twins Katie and Kelly, have been kidnapped. A man calling himself the Pied Piper demands a ransom of eight million dollars for the girls. Stephen's company agrees to transfer this amount to his account. But when the parents come to pick up the children, they find only Kelly in the car. The driver, who apparently committed suicide, admits in his suicide note that he accidentally killed Katie and threw her body into the sea. However, Kelly stubbornly insists that her sister is alive. Where is the girl and who is behind this kidnapping? Mary Higgins Clark is the recognized queen of detective stories, a master of twisted intrigue and unexpected plot endings. The total circulation of her books exceeds 100,000,000 copies.