An extraordinary fiction debut, Think of a Number is an exquisitely plotted novel of suspense that grows relentlessly darker and more frightening as its pace accelerates, forcing its deeply troubled characters to moments of startling self-revelation.Arriving in the mail over a period of weeks are taunting letters that end with a simple declaration, 'Think of any number.picture it.now see how well I know your secrets.' Amazingly, those who comply find that the letter writer has predicted their random choice exactly. For Dave Gurney, just retired as the NYPD's top homicide investigator and forging a new life with his wife, Madeleine, in upstate New York, the letters are oddities that begin as a diverting puzzle but quickly ignite a massive serial murder investigation.What police are...