A serial killer known as "The Whistler" has been terrorizing the women of London and detective Adam Dalgliesh (Roy Marsden) gets caught up in a search in this televised adaptation of P.D. James' best-selling mystery. With twists and turns around every corner, Dagliesh must navigate through an assortment of bizarre suspects to stop the murderer once and for all. Will he solve the case before it's too late?