Zadie Smith's brilliant tragi-comic "NW" follows four Londoners - Leah, Natalie, Felix and Nathan - after they've left their childhood council estate, grown up and moved on to different lives. From private houses to public parks, at work and at play, their city is brutal, beautiful and complicated. Yet after a chance encounter they each find that the choices they've made, the people they once were and are now, can suddenly, rapidly unravel. A portrait of modern urban life, "NW" is funny, sad and urgent - as brimming with vitality as the city itself.