In California's San Fernando Valley, any given day is likely to produce the unlikeliest of occurrences and coincidences. This is one of those days. While motivational guru Frank Mackey (TOM CRUISE) stirs up his all-male audience about how to nab women, veteran TV quiz show host Jimmy Gator (PHILIP BAKER HALL) is preparing for his next show that will feature whiz kid Stanley Spector (JEREMY BLACKMAN). Despite being a brilliant kid, he can't stand that his father, Rick (MICHAEL BOWEN), relentlessly pushes him in hopes of living vicariously through his success.
While Jimmy cheats on his wife, Rose (MELINDA DILLON,) and tries to made amends with their cocaine-addicted daughter, Claudia (MELORA WALTERS), he doesn't realize the damage his show can create. Case in point is Donnie Smith (WILLIAM H. MACY), a former child prodigy who's grown up into a disillusioned, middle-aged man. As such, he can't keep a job and wants dental braces so that he can be more like the male bartender that he's secretly in love with.
Meanwhile and across town, Linda Partridge (JULIANNE MOORE) is trying cope with her shattered life that includes her terminally ill husband, Earl (JASON ROBARDS) and the dual facts that she only married him for his money and has been cheating on him ever since. As she goes out to get more drugs to ease the last days of his life and contemplate considerably shortening hers, Earl awakens in a stupor, asking his at-home nurse, Phil Parma (PHILIP SEYMOUR HOFFMAN), to find his long estranged son.
While he does that, police officer Jim Kurring (JOHN C. REILLY) investigates a disturbance that leads to a dead body, a fact that Dixon (EMMANUEL JOHNSON), a streetwise young kid would like to help solve. Kurring has other calls to which he must respond, however, including one that leads him to Claudia's door.
As they begin a touch and go romance and Phil continues on his quest to find Earl's son, Stanley tries to cope with the pressures of performing, Frank deals with the probing questions of Gwenovier (APRIL GRACE), a visiting TV reporter, and Donnie drowns his sorrows with Thurston Howell (HENRY GIBSON) while plotting his revenge on his former employer. With each dealing with their own problems, a twist of fate and unexpected revelations soon affect all of them.