The Paley Center For Media's 34th Annual PaleyFest Los Angeles - 'Orphan Black' - ArrivalsKathryn Alexandre is the Ginger Rogers to Tatiana Maslany's Fred Astaire.

As the "Orphan Black" star's acting double when the many clone sisters Maslany plays appear in scenes together on BBC America's sci-fi thriller, Alexandre not only has to rise to the same performance level as the leading lady, she has to do it with her back to the camera.

"It was such a unique, wonderful experience," Alexandre told Moviefone. Maslany, of course, collected an Emmy last year for her jaw-dropping work playing multiple but diverse DNA-identical characters -- the determined central heroine Sarah, suburban housewife Alison, deadly but loyal Helena, hipster lesbian scientist Cosima, scheming Rachel and many more -- and Alexandre, who's a match for the star in both stature and commitment, has been playing all the same roles, just with her face obscured, since the very beginning.

"It was such a dream for an actor because it was completely selfless," says Alexandre. "My job was to give Tatiana as much as I could give her to make her be the best that she can be, so there was nothing that was egotistical about it, which was so freeing."

"It's hard to not follow your own impulses as an actor, in a way," she admits. "I have to play Tatiana's characters from her impulses. Because I inevitably play a character before she does in every scene, I'm trying to anticipate how Tatiana will play the character, and how Tatiana will kind of interpret the scene. So we're able to talk before. We're able to kind of rehearse, and she gives me a lot of freedom to play and explore."

"What we learned as the seasons went on was that the differences in how I play the characters are kind of really beautiful and important," Alexandre revealed. "That's what makes her reactions very genuine, because she's acting off a human being that's giving her something interesting and different, and alive as opposed to just looking at a mark of tape on the wall or a tennis ball."

Maslany recently told a PaleyFest audience she was in awe of what Alexandre delivered. "Kathryn and I were doing a scene and it's totally my coverage; it's a close-up of me and the camera is [inches away] on me, and Kathryn is next to the camera," remembered the star. "The camera's only on me, and she's giving me literally, like, 10 times what I was even remotely giving her on my side. An unbelievable performance, and it'll never be seen. And it's so frustrating. I couldn't even believe the generosity of it."

Alexandre admits that not all of the clones were always equally accessible for her. "Helena was so challenging for me," she says, "I liked playing her because I was scared to play her, which is a good feeling. Same with Sarah -- Sarah's very different than myself, so I was always scared to play her and go to the depths that she goes to. I'm a pretty quiet person, so to scream and to get really dirty and raw was tough for me."

"I had, kind of, fun playing Cosima and Alison because they're a little more predictable, they're a little more put together," she adds. "But the ones that kind of went to really far reaches from myself were challenging and exciting."

She's hoping that, very soon, she'll be showing her own face to the camera more frequently. "I've done some smaller roles on different shows," she says. "It's exciting to kind of move on and be completely open to new projects, so I'm excited to see what comes next for me."