Diablo Cody ("Juno") has written another nuanced, psyche-skewering masterpiece with "Young Adult". And Charlize Theron turns in an amazing performance that takes the audience along for a darkly comic and deeply rewarding ride. "Young Adult" centers on a woman, Mavis (Theron), who was all that back in high school. After a crushing divorce, she returns to her small town, Mercury, to regroup, and, she hopes, reclaim her high school flame, Buddy (the blandly handsome Patrick Wilson, also excellent). But unlike Mavis, Mercury and its residents have changed, and grown up. The reality checks that crash into Mavis don't always sink in, which of course is how this would be in real life. Mavis's focused cluelessness and sense of entitlement cause the viewer to cringe, but are also black-comedy funny. Comic Patton Oswalt is also a revelation, playing Matt, a sort of Greek chorus of Mercury who relates to Mavis (sort of) and isn't afraid of telling her the truth. Both Matt and Mavis peaked in high school, for different and heartbreaking reasons, but it's Matt who's the true adult and in charge of his life, and Mavis who, despite her beauty and achievements, is floundering. The cast includes welcome cameos by the talented actors Jill Eikenberry and Mary Beth Hurt, who are terrific comic foils. The deft direction of Jason Reitman and Cody's script give "Young Adult" its laughs, and its heft. When Buddy resists Mavis's advances, "But I'm a married man," Mavis, unblinking, replies, "I know! We can beat this thing together!" The viewer wants to slip off the seat, cracking up all the way. "Young Adult" is a truly interesting and nuanced comedy, and Charlize Theron will have the viewer thinking long after the film is over. --"A.T. Hurley"