Margot Lewis在英國的劍橋大學城一間貴族高中擔任教師。空閒時她為當地報紙一個名為「Dear Amy」的專欄撰寫文章。某日Margot 15歲大的女學生Katie意外失蹤，造成小鎮陷入一片恐慌。就在此時，Margot從專欄信箱收到一封匿名信，這是一封來自少女Bethan Avery的綁票求救信，最令人不寒而慄的是，這名少女早在20年前就已失蹤，至今仍下落不明。警方將信件的字跡與Bethan比對後，居然發現是本人親筆所寫，這起離奇的失蹤案引起犯罪學專家Martin Forrester的注意，嘗試找尋少女的蹤跡。兩名失蹤少女，兩起神秘失蹤案，相差20年的時間，綁架兩人的兇手到底是誰？就在Margot與Martin開始著手調查兩起案件的關聯性時，Margot卻意外成為兇手的下一個目標…。
In Helen Callaghan’s chilling, tightly-spun debut novel of psychological suspense, a teenage girl’s abduction stirs dark memories of a twenty-year-old cold case...
Margot Lewis is a teacher at an exclusive high school in the English university town of Cambridge. In her spare time, she writes an advice column, “Dear Amy”, for the local newspaper.
When one of Margot’s students, fifteen-year-old Katie, disappears, the school and the town fear the worst. And then Margot gets a “Dear Amy” letter unlike any of the ones she’s received before. It’s a desperate plea for rescue from a girl who says she is being held captive and in terrible danger—a girl called Bethan Avery, who was abducted from the local area twenty years ago…and never found.
The letter matches a sample of Bethan’s handwriting that the police have kept on file since she vanished, and this shocking development in an infamous cold case catches the attention of criminologist Martin Forrester, who has been trying to find out what happened to her all those years ago. Spurred on by her concern for both Katie and the mysterious Bethan, Margot sets out—with Martin’s help—to discover if the two cases are connected.
But then Margot herself becomes a target.