How do you catch a killer who is yet to kill? We all know the signs. Cruelty, lack of empathy, the killing of animals. Now, pets on suburban London streets are being stalked by a shadow, and it could just be the start. DI Tom Thorne knows the psychological profile of such offenders all too well, so when he is tasked with catching a notorious killer of domestic cats, he sees the chance to stop a series of homicides before they happen. Others are less...