In the summer of 2008, Callum, a four-year old boy goes missing at a neighbourhood barbecue. Five years later his body is finally discovered, buried only yards from his own front door. And so the nightmare for Callum's family and neighbours begins all over again. DCI Maggie Brand leads the new investigation. Her son, Sam, was born only a few months after Callum disappeared, and to her dismay he's recently been diagnosed with autism. Driven by her obsession to discover what happened to Callum, Maggie leaves no stone unturned in piecing together the events of that fateful night.