Laurel Canyon, a street that runs through the heart of the Hollywood Hills, has fordecades been a sort of Greenwich Village of the West, home to many musicians, actors,artists and other bohemian types. Among its current residents is Jane (FrancesMcDormand), a veteran record producer, trying to come up with a hit single for a British band whose lead singer Ian (Alessandro Nivola) is her much younger lover.
Jane's son Sam (Christian Bale) and his fiance Alex (Kate Beckinsale) are both recent graduates of Harvard medical school. Conservative and serious, the couple move to Los Angeles to complete their studies, planning to stay in Jane's home, which she had promised would be vacant. But when they arrive, Sam is distressed to discover Jane and the band still working in Jane's home recording studio. Jane's carefree lifestyle is anathema to Sam, who has devoted his life to being anyone but his mother's son. Sam and Alex begrudgingly agree to stay at Jane's house until they can find an alternative place to live.
Once in the house, however, Sam and Alex's tight control over their lives begins to unravel. Increasingly, Alex finds herself seduced by Jane and Ian, leaving Sam adrift, vulnerable to the approach of fellow medical resident Sara (Natascha McElhone).
The Brit-pop sounds of Ian's band and the sunbleached southern California landscape set the tone for this rigorously honest exploration of relationships between people with wildly divergent world views.