Anna lives a solitary existence, taking solace in order and routine. Her only friend is the lonely old lady next door. She doesn't like to let people to get too close - she knows how much damage they can do. Then one oridnary day Anna witnesses a devastating road accident and recognises the driver as Carla, the woman who ruined her life all those years ago. Now it's Anna's chance to set things straight but her revenge needs to be executed carefully... First she needs to get to know Liam, the man injured in the accident. She needs to follow the police investigation. She needs to watch Carla from the shadows... But as Anna's obsession with Carla escalates, her own secrets start to unravel. Is Carla really dangerous or does Anna need to worry about someone far closer to home?