For eighteen years the Hartes and the Golds have lived next door to each other, sharing everything from takeaways to school drop-offs. So it's no surprise when teenagers Chris and Emily, soul mates since they were born, start dating. When the late-night call comes in from hospital, no one is prepared for the appalling truth: Emily has died from a gunshot wound to the head as part of an apparent suicide pact. The gun holds a single unspent bullet that Chris tells police he intended for himself. But the local detective has his doubts, and in the wake of this unthinkable act, two devastated families must ask themselves: how well do we ever really know our children?