As a surveillance specialist Tom Welles (Nicholas Cage), has a modest home-based practice in Harrisburg Pennsylvania handling mainly routine cases such as checking up on unfaithful spouses. His assignments, whilst supporting the life he shares with his wife and baby daughter, do not inspire him greatly, there is no danger or mystery to any of his cases, until now. When a small innocuous 8mm reel of film comes into Welle's possession, his life is turned upside down. The film which contains graphic and disturbing material sends Welle’s on a mission through LA’s seedy Hollywood Boulevard sidewalks to the squalor of New York City’s meat-packing district to determine the fate of a complete stranger, a girl who begins to haunt his imagination and conscience. Aided by a streetwise adult bookstore clerk, Welles’ drifts away from his wife family and former life.