A voice cried for help. No one found it. Claire heard it... and she cannot forget. The danger could be closer than she imagines. A 911 call comes in: a terrified woman says a van is pursuing her. Dispatcher Claire Sutton listens, powerless, as the woman is abducted in real time on the other end of the line. The police, however, find nothing: no victim, no evidence, no originating number. Only dead air. To everyone else, it is a prank call. To Claire, it is something more. That voice pleading for its life, shaky and broken, echoes the voice of her sister Lucy, who vanished twenty years ago under circumstances extraordinarily similar to those reported by the woman who called: she was taken by a white van right before Claire's helpless eyes. As the system dismisses the call, she decides to investigate on her own. She soon discovers other similar calls, all filed as false alarms and all following the same pattern: a terrified woman claiming to be followed by a white van. Claire cannot stop digging, even as everyone around her opposes it. The most disturbing part is that no one knows her sister's story, yet whoever is behind all of this knows and is taunting her. Could someone inside the emergency call center itself be involved? In a city where voices get lost on the line, Claire must confront her past and figure out who is behind the macabre game before the silence claims another victim.