An obsessive and likely disturbed woman named Mary Horowitz (Sandra Bullock) thinks there is some merit in stalking a CNN news cameraman named Steve (Bradley Cooper). Having one date with the man, she goes into a compulsive mode when nothing else consumes her like attaching herself to this unwary man. With her independent career, she is able to fund her travels and have time to pursue the unfortunate victim. She finds encouragement from a reporter named Hartman Hughes (Thomas Haden Church) whose purpose is to bedevil Steve. In that obsessive demeanor Mary Horowitz begins to make news, driving Steve into a desperate and disturbed state of mind.