What if the people we trust are the ones we should fear?We all recognise them. Those who sit just on the fringes of society. Who send prickles up the back of our necks. The charmers. The liars. The manipulators. Those who have the potential to go that one step too far. And then take another step.Jessamine Gooch makes a living from these people. Each week she broadcasts a radio show looking into the past lives of convicted killers, asking if there was more that could have been done to prevent their terrible crimes.Then one day she is approached by a woman desperate to find her missing friend, Cassie, fearing her abusive husband may have taken that final deadly step. But as Jessamine delves into the months prior to Cassie's disappearance she fails to realise there is a dark figure closer to home, one that threatens the safety of her own family ...