Adam, a nine-year-old autistic boy, is discovered hiding near the body of his classmate. They had wandered away from the school playground hours earlier, and now Adam is the only witness to an appalling crime. But he can't tell the police what he saw or heard. Barely verbal on the best of days, Adam has retreated into the silent world that Cara, his mother, knows well. With her community in shock and her son unable to help with the investigation, Cara tries to decode the puzzling events. Adam has never broken the rules before, so why did he disappear with the little girl? Cara, a single mother, has devoted her life to opening paths of communication between her son and the outside world. Now, she must interpret the changes in Adam's behavior to help him through the trauma, and to catch a killer.