Elisabeth Moss on “Mad Men,” “The Children’s Hour” and working with Keira Knightley

On Mad Men, Elisabeth Moss plays Sterling Cooper Draper Pryce’s ambitious copywriter Peggy Olson. Her performance as a secretary-turned-career-woman has made her a fan favorite and Elisabeth has been nominated for several awards throughout the show’s first four seasons.

With the fifth season finally coming to AMC this month, Moss will be back on our screens in her 1960s sweater sets this spring. While at a TCA cocktail party with her cast and the show’s creators, the actress told me she couldn’t say anything about the new episodes, other than she’s having a lot of fun.

“I’m proud of where [Peggy’s] going. I’ve had a lot more fun this season than any other season, and I’ve had a lot of fun on other seasons,” Elisabeth said. “It’s just been fun to play her. I think she has reached a really fun place.”

Season 4 saw more of Peggy opening up in her personal life as she began hanging out with some artists and beatniks she met through Life magazine photographer and out lesbian character Joyce (played by Zosia Mamet). Although Peggy doesn’t seem to be interested in Joyce sexually or romantically, she is drawn to the lifestyle the creatives lead and began to spend more and more time in Joyce’s world.

Since Mamet has been busy in her new role on HBO’s Girls, I had to know if we’d see more Joyce on Season 5 of Mad Men. Unfortunately, Elisabeth just can’t tell us anything.

“I can’t say, I’m sorry!” she said. “Really I can’t!”

While Elisabeth was on hiatus from the show, she acted alongside Keira Knightley in The Children’s Hour, the famous stage play that centers around two female friends who run a boarding school and have their lives ruined when a pupil starts a rumor they are lovers. Moss said she loved her time working on the play in London.

“Theater is the hardest and best thing an actor can do really, and it’s a difficult experience, but it’s a really empowering experience as well,” Moss said. “It’s a great play. I love Lillian Hellman and it’s a beautiful play.”

Elisabeth said she’d dreamt of performing in the West End and also loved the cast and director, Ian Rickson. She said of working alongside Keira, “She’s a really wonderful girl. She’s very hard working and very serious about what she does. I was very lucky.”

I think Keira was lucky as well.

Mad Men‘s fifth season will premiere on March 25.