A successful "house tuner" in New York City, who calibrates the sound in people's homes in order to adjust their moods, meets a client with a problem he can't solve.
A nightmarish evening unfolds for neighbors David and Robert when they accidentally hit a woman on her bike and flee the scene. While David is increasingly plagued by feelings of guilt, Robert shows no remorse and becomes overbearing and possessive.
A psychotic man opens fire in a diner, murdering numerous people before killing himself. The survivors struggle in different ways following this horrendous event: a doctor doubts his own instincts and elects to use an experimental medical procedure on his wife, while a gambler believes he's on a lucky streak. A waitress begins engaging in promiscuous sex, and a young girl whose father is among the dead gains unexpected fame.