Sarah Paulson has been an American Horror Story regular for all four seasons. However, no season has required the amount of effort as Freak Show.
In FX's newest installment in the horror franchise, Paulson plays conjoined twin sideshow performers Bette and Dot Tattler. As you can imagine, it's not an easy shoot for Paulson.
"It's the hardest thing I've ever done," Paulson told ET's Kevin Frazier on the red carpet outside Elle's Women In Hollywood celebration, where her AHS co-star Jessica Lange was being honored for her work.
"It's the most exhausting thing I've ever done. And for all the other actors, it's one of the hardest things they've ever had to do. Because when I'm shooting, I've got one head, and they have to imagine where the other head is going to be."
VIDEO: This American Horror Story: Freak Show Clown Will Haunt Your Dreams
"It takes a long time," Paulson added. "But I think it looks incredible."
Paulson also talked about her co-star Jessica Lange, and whether she would be returning for the next season.
"I don't know what American Horror Story would be without her," Paulson, 39, said. "I hope she stays. I wish I could say I have some insight, but I've got everything I could possibly cross -- I've got both heads crossed."
VIDEO: Jessica Lange Performs David Bowie's 'Life On Mars' on AHS: Freak Show Premiere
As for Lange, she's not letting on about her future AHS plans either. Frazier caught up with the night's special guest, and asked her about her plans for season 5.
"I'm so deep in the series at this point in this season that I can't even think about next year," Lange, 65, said.
Check out the video for more from the brilliant stars of the twistedly entertaining American Horror Story: Freak Show, which airs Wednesdays at 10pm on FX.