That face, composed in its porcelain smile, is a shield with which Bree Van De Kamp meets the world.
As any viewer of "Desperate Housewives" knows, Bree has plenty not to smile about. Last season her husband died -- and worse (as she discovered later) it was at the hand of George, her twisted admirer. Then this murderous swain offed himself in an ill-advised gamble that Bree would demonstrate her love by saving him from his drug overdose.
Meanwhile, Bree's teenage son is scandalizing her by coming out of the closet. And she seems to have developed a drinking problem.
Even with Bree's defensive smile, it's mighty hard to keep up appearances on Wisteria Lane!
But here is Marcia Cross on break from playing Bree, and she presents quite a different picture. Oh, the red hair and porcelain skin are the same. But in person, Cross comes across as far more delicate and vulnerable than Bree would permit for herself on the hit ABC series (9 p.m. EST Sunday).
Indeed, Cross is focusing on a lifelong vulnerability. As a paid spokeswoman for GlaxoSmithKline, maker of a migraine headache medication, she wants to talk about her long affliction with migraines, and what she's done to combat it.
"I suffer from a classic migraine," says Cross, 43, whose headaches began when she was 14. "My fingers tingle, and I see a very odd sort of aura in my peripheral vision. I know when it's coming on, and I take my medication, and in a number of hours I'm back on my feet again.
"But before that, I was knocked out and writhing in pain, and it was horribly excruciating."
Besides the introduction of such medicine in recent years, Cross has benefited from her increased understanding of stress and diet management.
"I feel that I have a handle on it," she declares.
Of the more than 28 million Americans who suffer from migraines, three times more women than men are affected -- and tightly wound, control-freak Bree would seem to be a ready candidate.
Cross laughs at the thought of her own ailment imposed upon Bree. But then it dawns on her: The idea might just work.
"I might have to ask Marc about putting it in," she muses.
She is referring, of course, to "Desperate Housewives" mastermind Marc Cherry, who created Bree and the dishy dames played by Cross' co-stars Teri Hatcher, Felicity Huffman, Eva Longoria and Nicollette Sheridan.
"I'm still pinching myself, I really am, at my good fortune" at being signed for the show, says Cross, for whom lightning has struck twice: In the 1990s, she starred on another wildly popular series, the Fox soap "Melrose Place," where she played a love-plagued, wacko doctor.
"I never thought I would live Kimberly Shaw down," says Cross with a laugh. "So the fact that I've got another character, very different, under my belt is great."
Each show ranks as a cultural phenomenon, but Cross points out that, unlike "Desperate Housewives," "Melrose" was never exactly a critical favorite.
"It's very nice to be able to do your work and be respected for it," she says. "It's not that my work is any different, because I always took 'Melrose' very, very seriously. I would pretend it was some really important film, every day. But I don't have to make any excuses for this one."
Even so, sometimes she feels the urge to make excuses for Bree and her deviant behavior.
"I'm given a script and I'm always saying to Marc, 'Please don't make me do that!' When I had to let George die, I had three meetings with Marc, begging him. And he was like, 'Marcia, trust me. Have I let you down yet?'
"So I was pushed to go find that reality for myself. But I'm always kind of appalled and shocked by where she goes."
Is Cross saying it shocked her that Bree would sit and watch George die, even out of vengeance?
"It did!" she winces. "It was horrific!"
Maybe her reaction is connected with her lifelong interest in human behavior -- a level of curiosity that fueled her drive to earn a master's degree in psychology.
"I'm so fascinated with the mind and consciousness and everybody's story," she says. "It's kind of why we're here, I think.
"My fiance," she goes on, referring to businessman Tom Mahoney, whom she plans to wed this summer, "just watched me salivate getting a new book from Amazon.com on psychoanalytic techniques. I couldn't wait to open it."
All of which suggests that Cross might be uniquely qualified to analyze her "Desperate Housewives" alter ego.
Bree is "certainly not psychotic," Cross begins. "She's just a garden-variety, highly neurotic functioning human. So I would just want to get her to be more able to feel, and integrate her feelings -- cause that's where the trouble comes from, a lot of it.
"I think she would be a very interesting patient," says Cross affectionately. "I'd recommend she come three times a week."