New York City radio host Erica Bain is working and living a wonderful life. One night she and her fiancé David are brutally attacked. David is killed and Erica is almost beaten to death. Traumatized and unable to cope with the tragic event, Erica becomes someone else. She buys a gun and begins to roam the streets at night looking to take her revenge on the men who were responsible for the attack. Late one night, she is in the back of a convenience store when a robber comes in and kills the store clerk and his wife. The robber comes after her but she protects herself, finding that it is very easy to shoot a gun. Later, Erica finds herself confronted by two would-be rapists on the subway, and again she protects herself. The city becomes fascinated with the exploits of this vigilante killer, but NYPD Detective Mercer is trying to catch this person, before they strike again.