It's been almost six months since the 29-year-old actor's cinematic debutante ball, Atonement, was in theaters. In the Best Picture-nominated adaptation of Ian McEwan's novel, McAvoy plays Robbie Turner, a housekeeper's son with a Cambridge education who falls in love with the daughter of an upper-class family. The embryonic affair is extinguished by a false accusation of sexual assault against Robbie, who ends up dying on the beaches of Dunkirk in World War II.

American audiences had seen McAvoy before, most notably as Mr. Tumnus the Faun in The Chronicles of Narnia and as the unscrupulous doctor who becomes Ugandan dictator Idi Amin's physician in 2006's The Last King of Scotlanda performance lauded by critics, despite the fact that McAvoy was laboring in the almost comically large shadow of Forest Whitaker. But delivering McAvoy to multiplexes as the soulful-eyed young lover in Atonement was like taking the plastic wrap off a piece of Kobe. In New York doing reshoots for Wanted, the comic-book-based action movie out this month in which he costars with Angelina Jolie, the actor has gotten unprecedented attention.

McAvoy in the trailer for The Last King of Scotland

"It was surprising coming here, because I've been recognized more than ever," he says, sitting down at a Ukrainian diner. That shift isn't immediately apparent in this setting, where the weekday crowd consists mainly of a few elderly people and a woman cradling a drowsy baby, whom McAvoy entertains with some clown faces. By the time his lentil soup gets to the table, no one's looked up from their blintzes. Then the waitress drops a black leather check holder on the table, explaining that it's been sent from the other side of the room. McAvoy opens it, takes out a napkin, and reads the note written on it. He turns around and cranes his neck to look for the sender. In the back, by a row of windows, a middle-aged woman waves enthusiastically.

If James McAvoy gave you the look, you would know it. It would pierce your heart like a tiny dart hocked from a hollowed-out piece of wood. Paul Abbott, who wrote the TV show that made McAvoy a star in the U.K. almost five years ago, has been a recipient of the look. Abbott created Shameless, a loosely autobiographical show about a lower-class family in Manchester, England, in which the oldest sister (British actress Ann-Marie Duff, now McAvoy's wife), in charge of raising her siblings, dates a slick criminal played by McAvoy.

McAvoy in Shameless

At one point during filming, Abbott spoke to the press about the similarities between the premise and his own upbringing. When he offhandedly told this to McAvoy, who grew up in less-than-ideal circumstances himselfthe child of a divorce raised mostly by his grandparents in the projects outside Glasgowhe was met with the look. "It wasn't even a frown," Abbott says. "It was just like his pupils dilated or something.... He made me feel like a whore a little bit."

McAvoy doesn't remember eviscerating Abbott with his eyes, but he fully admits to being critical. "I judge people very quickly" he says. "There was someone I worked with recently who, within five minutes, displayed all the attributes of a fucking dick, and I gave them the benefit of the doubt. Weeks later I was still there, going 'You're so fucking self-obsessed.' I've spent a long time giving people the benefit of the doubt, and I'm tired of it."

Combine that appraisal with a confession that even in his early twenties he never really liked to go out ("All of my friends got so drunk they couldn't even walk, let alone dance, and you just stand there going 'So what am I going to do?'") and a tangent about lookism in pop culture ("I saw a clip of somethingthis girl has on a humongous fat suit and she's singing that 'my milk shake brings all the boys to the yard' song, and I just felt like, 'That's so disrespectful.' I would not want to be a woman in this industry. Horrible."), and a portrait of McAvoy begins to emerge. It looks a little like a prim, white-wigged 18th-century magistrate.

The reality, says Atonement director Joe Wright, is less stiff. "James is someone who's had to fight," Wright says. "He understands emotional and psychological pain. But I think his natural temperament is very light and very comic." He uses the same word that Abbott does to describe McAvoy: dignified.

McAvoy in the "library scene" from Atonement

Wright first saw McAvoy perform in 2001 in London, in a play called Out in the Open. He had just graduated from the Royal Scottish Academy of Music and Dramaone lily pad in the series that every actor from the U.K. seems to traverse before he lands on this side of the pond: a hard-knock childhood in a factory town, a few years at arts school, and a couple of stage appearances that lead to a breakout role in a TV show. But certain details bring McAvoy into sharper focus. There are the grandparents, whom he mentions regularly in conversation (his father left the family when he and his younger sister, Joy, were in grade school). There's the time in high school when he played bass in a band, something he wasn't very good at but which served as a meandering tributary into acting. There's Duff, his wife, eight years his senior. But ask for more details about her, his sister, or any other key figures in these vignettes and you'll get another looka defensive one that's much different from the silent-poison-dart one. It's a lot like the one Matt Damon gives Robin Williams when he walks in for his first therapy session in Good Will Hunting.

"If anybody wants to talk about their own family, fine," he says. "It's not that I think it's wrongit's just that I think it's dangerous."

On the phone from Germany, where he's just finished a day's work on The Last Station, a film based on a novel about the life of Leo Tolstoy, McAvoy is apologizing for the effects of having just had a swig of beer. He's trying to recollect what compelled hima small, slight action-movie virgin with an antipathy for gunsto take an aggressively physical role opposite genre veteran Angelina Jolie. "I think inside all actors," he says, "there's a kid who secretly yearns to jump off buildings and say 'Yippeekayay, motherfucker!' I also thought that the fact that they were willing to cast someone like me showed a willingness to step outside the usual action-movie realm." Movie-industry pundits are translating that statement into: "I want to be like Matt Damon and do a hugely successful thinking-man's action franchise like Bourne." But by the time those parallels are drawn, McAvoy will have monkey-swung from completing the Tolstoy movie, as part of an ensemble cast that includes Paul Giamatti and Helen Mirren, to, no doubt, portraying somebody who bears little resemblance to a vengeful action hero or a Russian bibliographer. About the only certainty is that McAvoy wants to enjoy himself. "Hugh Grant is fucking great and he's funny," he says. "I like romantic comedies. I've been in one and I fucking loved it. I got to show off and I got to be a dick. It's always fun to play dicks. That's why I loved Last KingI got to be such a wanker."

McAvoy in the trailer for Wanted

"Someone like James, I would guess, would strive to play the opposite of what he's been made to believe he is as a unit of currency," Abbott says. "I've watched James being pursued by people who want to pin him down, and whether he knows it or not, he's just slid like a bar of soap right out of their hands."

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