NEW YORK -- Sitting down for breakfast on a recent rainy New York day, Michael Shannon was uncertain about the prospect of food.
"They say you're supposed to eat breakfast," he said, pondering the option. "You don't eat breakfast, you'll go crazy."
The possibility wasn't a remote one: Shannon has never shown a reluctance to do exactly that.
In parts like the obsessively upright, self-flagellating federal agent on HBO's "Boardwalk Empire"; the unbalanced, truth-telling neighbors' son of "Revolutionary Road"; and in "Take Shelter," the actor's latest, a small-town Ohio family man increasingly haunted by apocalyptic nightmares, Shannon has unflinchingly followed his characters into paranoia, anxiety and derangement.
In the end, coffee was judged sufficient, but nothing close to insanity followed.
Shannon, 37, proved that it's not his imposing size -- 6 feet 3 inches with a rock square jaw -- or his ability to dramatically come unhinged that has made him one of the most admired actors around. It's his underlying sensitivity -- his empathy for his characters and his attuned senses to his sur-roundings -- that more properly defines Shannon.
"The characters I play, it's not like they're all in the asylum, separate from the rest of us," he says. "I react to things. I think the world is an unsettling place. I have some anxiety about it. Maybe that comes through in what I do. But it's not something I'm attempting to do."
The source of Shannon's paranoia in "Take Shelter," written and directed by Jeff Nichols, is the movie's mystery. Is his character losing it, like his mother did at his age? Or is the perceived threat real and outside his family?
Shannon's performance, a carefully calibrated ball of tension and encroaching mania, already has earned him an underdog place in this year's Oscar prognostications for best actor. After years of character actor and stage work, it's the fullest cinematic display yet of Shannon: unadorned and still powerfully intense.
"I was really floored by his power and stillness," says Jessica Chastain, who plays his wife in the film. "He has this great source of energy, but the stillness contains this great power and intense emotion."
In choosing his parts, Shannon generally is drawn to the material, comparing good writing to a Faberge egg that needs an actor's protection.
In the case of "Take Shelter," he identified with Nichols' (and the script's) anxiety over starting a family. Shannon lives in Red Hook, Brooklyn, with his partner, actress Kate Arrington, and their 3-year-old daughter.
"In my 20s and the first third of my 30s, I lived a very gypsy lifestyle," says Shannon. "It didn't really matter where I lived. ... Now I have a home and a family. ... So it's on my mind."
Shannon acknowledges he's been pigeonholed for playing disturbed characters and notes it's "something I struggle with." I'm certainly not going to do a $5,000 movie about a serial killer ... about a guy who grinds people up or saws people," says Shannon.
On "Boardwalk Empire," which is now airing its second season, his character, Nelson Van Alden, has morphed from an Eliot Ness-type, to a religious zealot who punishes himself for his lust for a woman not his wife. In the show's first season, he had a remarkable scene where he baptized a double-crossing colleague, drowning him.
"When Michael commits, he commits," says "Boardwalk" creator Terence Winter. "We look at Nelson Van Alden as this religious zealot who maybe has a screw loose. Michael's approaching it from the inside out, as a real man."
In the much-anticipated upcoming Superman film, Zack Snyder's "Man of Steel," he'll play General Zod, the villain earlier played by Terence Stamp. Thinking of working that film, which is shooting, in comparison to "Take Shelter," Shannon says: "There's not a word for how different it is."