In a rivetingpsychological thriller, Mary Higgins Clark takes the reader deep intothe mysteries of the human mind, where memories may be the mostdangerous things of all.At the center of hernovel is Kay Lansing, who has grown up in Englewood, New Jersey,daughter of the landscaper to the wealthy and powerful Carringtonfamily. Their mansion -- a historic seventeenth-century manor housetransported stone by stone from Wales in 1848 -- has a hidden chapel.One day, accompanying her father to work, six-year-old Kay succumbs tocuriosity and sneaks into the chapel. There, she overhears a quarrelbetween a man and a woman who is demanding money from him. When she saysthat this will be the last time, his caustic response is: "I heard thatsong before."That same evening, the Carringtons hold a formaldinner dance after which Peter Carrington, a student at Princeton,drives home Susan Althorp, the eighteen-year-old daughter of neighbors.While her parents hear her come in, she is not in her room the nextmorning and is never seen or heard from again.Throughout theyears, a cloud of suspicion hangs over Peter Carrington. At ageforty-two, head of the family business empire, he is still "a person ofinterest" in the eyes of the police, not only for Susan Althorp'sdisappearance but also for the subsequent drowning death of his ownpregnant wife in their swimming pool.Kay Lansing, now livingin New York and working as a librarian in Englewood, goes to see PeterCarrington to ask for permission to hold a cocktail party on his estateto benefit a literacy program, which he later grants. Kay comes to seePeter as maligned and misunderstood, and when he begins to court herafter the cocktail party, she falls in love with him. Over theobjections of her beloved grandmother Margaret O'Neil, who raised herafter her parents' early deaths, she marries him. To her dismay, shesoon finds that he is a sleepwalker whose nocturnal wanderings draw himto the spot at the pool where his wife met her end.SusanAlthorp's mother, Gladys, has always been convinced that PeterCarrington is responsible for her daughter's disappearance, a beliefshared by many in the community. Disregarding her husband's protestsabout reopening the case, Gladys, now terminally ill, has hired aretired New York City detective to try to find out what happened to herdaughter. Gladys wants to know before she dies.Kay, too, hasdeveloped gnawing doubts about her husband. She believes that the key tothe truth about his guilt or innocence lies in the scene she witnessedas a child in the chapel and knows she must learn the identity of theman and woman who quarreled there that day. Yet, she plunges into thispursuit realizing that "that knowledge may not be enough to save myhusband's life, if indeed it deserves to be saved." What Kay does noteven remotely suspect is that uncovering what lies behind these memoriesmay cost her her own life.