David Kirmani is an American bachelor, who works as an Medical Professional, lives alone in an apartment with his dog and sweetheart, Erica Bain, who works as a Radio Host. They usually take their pet out for a stroll in a nearby park and let him run and fetch. One day while at the park they let the pet run without a lease, and when he does not return nor respond to their calls, they frantically search for him. They eventually find their pet being held by three men, who want a reward, and when David refuses, they start to molest Erica, David intervenes, both he and Erica are assaulted by two males, while the third uses a camcorder to film this incident. Erica is knocked unconscious, and regains her senses several days later in a hospital. It is here she will be told the shocking news that David is no more and the pet is missing. A traumatized Erica returns home to try and regain her life. She also attends the Police Station but does not get much help. Fearful of a repeat of this type of incident, she gets an unlicensed gun and carries with her all the time. One day she witnesses some youth terrorizing subway passengers, forcing them to alight at the next station. When they approach her, she shoots them dead. She uses her gun several times thereafter, always gunning down people committing violent crimes. One day she is asked to attend the Police Station to identify a male who may have been responsible for David's death and the Assault on herself. She does recognize him, but refuses to identify him. Subsequently she finds out his whereabouts - and is all set to avenge her lover's death - not realizing that Detective Mercer has her as a suspect in the recent killings and is all set to apprehend her. The question remains will Erica be able to avenge David's death and the assault on herself?