Kate Winslet operates at a galaxy-class level in Little Children, Todd Field's gratifyingly grown-up look at unhappy suburbia. Winslet is magnificent, in an Oscar-nominated performance, as a stroller-pushing mother who becomes attracted to a passive househusband (Patrick Wilson). Their slow-burning infidelity (Field wisely allows time to pass in this unhurried film) is contrasted with a more sensational subplot, about a convicted pedophile (Jackie Earle Haley, also Oscar nominated) returning to the neighborhood to live with his mother (Phyllis Somerville). Field, who brought his civilized approach to In the Bedroom, uses a deliberately literary style here, including a device with a narrator who sounds as though he's sitting at our side as he reads from Tom Perotta's novel. (The narrator is a superb touch--his cultivated voice distances us from the sloppy passions of the characters.) The film's biggest miscalculation is a self-appointed neighborhood vigilante (Noah Emmerich) determined to make life miserable for the paedophile. But Wilson is appropriately nebulous, Jennifer Connelly solid as his wife, and Haley (child star of the Bad News Bears movies), as the creepy, childlike molester, found himself rediscovered after a long career layoff. There's decent acting here, but Winslet is in a zone of her own, with so much emotional honesty and subtlety of expression that she transforms a good movie into a must-see. --Robert Horton