Knock KnockThe #1 international bestselling thriller that tells the electrifying story of a police inspector and a former criminal informant in a race against time as they attempt to unravel past and present secrets. He thought she was safe. Then the past came knocking. Seventeen years ago, Criminal Inspector Ewert Grens was called to the scene of a brutal crime. A family had been murdered, and the only survivor and witness was the five year old daughter. The