After trying her hand at Thackeray with Vanity Fair, director Mira Nair has found a literary property much closer to her heart: Jhumpa Lahiri's best-selling novel about a Bengali couple and their children trying to find their place in American culture. The first part of the movie focuses on the parents, a college professor and his wife by arranged marriage (Bollywood stars Tabu and Irrfan Khan); the second belongs more to their headstrong, Americanized son (Kal Penn, earning his dramatic stripes after a series of collegiate comedies) as he grows to appreciate his roots. Connecting these two stories is a profound sense of identity being passed from one generation to the next, as the power of a great culture is personalized in a father's love for his son. PG-13, 122 min. a Century 12 and CineArts 6, Landmark's Century Centre.