Lily Gullick lives with her husband Aiden in a new-build flat opposite an estate which has been marked for demolition. A keen birdwatcher, she can't help spying on her neighbours. Until one day Lily sees something suspicious through her binoculars and soon, her neighbour is found dead. Lily knows that she has to act. But her interference is not going unnoticed and as she starts to get close to the truth, her own life comes under threat. But can Lily really trust everything she sees?