The day that radio essayist Erica Bain selects wedding invitations, her fiancé is murdered and she brutally assaulted while walking their dog in Central Park. Upon release from hospital, she buys an illegal handgun. When she witnesses a shooting in a convenience store and is stalked by the killer, she kills in self-defense but flees the scene. More incidents follow that she could have avoided. She walks the night streets a vigilante, a stranger to herself. A detective, Mercer, notices her and becomes her friend as he hunts for the killer. How long before he figures it out? Meanwhile, the methods of the police start to pay off in finding her fiancé’s killers. What now?