Amy was once a party girl, but now she lives a lonely life. Helping the house-bound to receive communion in the Gravesend neighbourhood of Brooklyn, she knows the community well. When a local woman goes missing, Amy senses something isn't right. Tailing the woman's suspicious son, she winds her way through Brooklyn's streets. But before she can act, he is dead. Captivated by the crime she's witnessed and the murderer himself, Amy doesn't call the cops. Instead, she collects the weapon from the sidewalk and soon finds herself on the trail of a killer. Powerful and evocative, The Lonely Witness brings Brooklyn to life and exposes the harsh realities of crime and punishment on the city streets.