Kenneth Lonergan's Margaret stars Anna Paquin stars as Lisa, an emotionally immature, overly-articulate 17-year-old Manhattanite with an emotionally carnivorous actress for a mother and a distant businessman father who lives on the West Coast with his new, younger wife. One day, while trolling the upper west side for a cowboy hat, she spots a bus driver (Mark Ruffalo) sporting the perfect ten-gallon headwear. She tries to get his attention, and, while distracted, he causes a fatal accident.
After the bus driver is found to be faultless, due in part to Lisa's initial statement to the police, she seeks out the victim's best friend (Jeannie Berlin) and together they find a lawyer willing to bring a case against the bus company as well as the driver. Meanwhile, she's still dealing with all the regular stress in her life including a nice guy with a crush on her, a jerk who she calls when she's ready to lose her virginity, her mother picking fights with her so that she can get emotionally worked up enough to be marvelous on stage, hating her father's new wife, and verbally destroying any classmate who express the slightest bit of empathy for Muslims (Lisa is still full of righteous anger 5 years after 9/11).
Margaret was the subject of much turmoil during a lengthy post-production period in which the director attempted to get a longer cut of the film released to theaters.