On the set of 'Mad Men' with Christina Hendricks

Looking at Christina Hendricks on the downtown Los Angeles sets of AMC's Mad Men, it's hard to believe that when Matthew Weiner created the series, he initially imagined Sterling-Cooper's bossy Queen Bee Secretary Joan as a tart, older woman, a Thelma Ritter type.

"Based on what he's told me, he imagined her as more of a curmudgeon, kind of comedy relief, a little bossy, a little tightly wound," notes Hendricks, who couldn't possibly be less of a Thelma Ritter type. "I think I was sort of a little bit more female-ish, a little bit more overtly sexual and little bit more competent than maybe he had imagined the character."

Weiner has said that Hendricks' interpretation of the role instantly caused him to reconceive the character. And for her part, Hendricks says that an essential element of finding the character was the early-1960s costumes. Surrounded by reporters in a Mad Men prop room, Hendricks is wearing a loose white top with purple flowers, looking more fresh-faced and relaxed than Joan would ever let herself be seen.

"I'm sure men feel this way too, but certainly we do as women, the way we choose to dress in the morning, it's how we've decided to present ourselves to the the world and I know that when I wear something like this, it feels more fun and useful, I act like that and when I'm in something more sleek and black, I feel like I act more elegant," she says. "I think putting on Joan's outfits, all of a sudden, I'm Joan, because I don't dress like that normally, although I probably should, because it's sort of fabulous... You put on the hair and the makeup and you really do feel different."

It helps that costumer Janie Bryant, like the men of Sterling-Cooper, is a big fan of Joan's form-fitting outfits.

"I think she really likes Joan's clothes, which is funny, because to me all of them are like so special," Hendricks says. "Every time I see January [Jones] she's in some dress that looks like a festival, I'm like, 'Oh my gosh, you're like dream, like a cotton-candy cloud.' And [Elisabeth Moss] gets to wear these smart little things that I think look like they could be Prada now, I just think they look incredibly stylish and amazing on her. We're all so completely different and Janie loves to make the special little belt and the little buttons and all the little details. She'll put it on and go, 'Christina!!!' She gets excited about every little detail and it makes it fun to do fittings with her."

Joan, with her strict code of secretarial conduct and period-specific view of workplace ethics, has often had difficult-to-read motives, but Hendricks has a solid read on the character.

"I think it's important as an actor to always find out how someone justifies their behavior," she says. "No one goes about doing something to be mean. They do it for a reason. I had to figure out the reason Joan's behaving like this is that she thinks she's being helpful, she thinks she's running a tight ship and this advice and this kind of behavior help things run smoothly and she thinks it's going to benefit the people around her. And I truly believe she thinks that, so when she says things to Peggy or to people in the office that seem mean, she really is like, 'This is the truth. You may not want to hear it, but it is. And if you follow my advice, things will go better for you.'"

One character who hasn't followed Joan's advice, of course, is Elisabeth Moss' Peggy, whose move out of the steno pool was one of several character surprises in Season One.

"I think she's baffled," Hendricks says of her character's reaction to the young upstart. "In every episode of Mad Men, you see a sea of women in the secretarial pool and each one of those girls came in and Joan walked each one of those girls through, just like she did Peggy, and they all listened to her, or are trying or are working through these things. And here's this young girl who isn't dressing the way she's been told to dress, who is pursuing what seems to be a man's career; Joan can't figure out how that's going to possibly get her a husband. It's not that she's jealous. I think she's just absolutely befuddled."

Viewers will learn several new things about Joan in this Sunday's (Aug. 3) episode, including the character's real age and how she handles competition. Hendricks hopes there are many more things to learn.

"These characters aren't on one path going straight-forward and if you watch Episode One, then you'll know the end result by Episode 13, because these characters are taking two steps to the right, one back, four to the left and maybe three forward," Hendricks says. "There are all these beautiful storylines along the way. I want to know so much about all of them. I think that with each step that they take, it just opens up doors this way and doors this way and doors this way."