EXCLUSIVE: 'AHS' Actress Adina Porter Survives Long Enough to Become the 'Roanoke' Breakout Star

"I'm a working actor and I'm really appreciative to be a working actor, but it's another level when you're a working actor with the likes of Sarah Paulson and Angela Bassett. I knew, 'OK, I have to bring my A-game because this is how these people operate -- especially Miss Paulson,'" Adina Porter tells ET by phone as she waits to board a flight back to Los Angeles from Vancouver, where she's currently filming the CW's The 100. The actress, who is probably most famous for playing Lettie Mae Thornton on HBO's True Blood, is the breakout star of this season of American Horror Story opposite Bassett, Paulson and Cuba Gooding Jr.

While dubbed a newcomer to American Horror Story, Porter's initial introduction to Ryan Murphy's anthology series came playing Sally Freeman, a patient of psychiatrist Ben Harmon's (Dylan McDermott) on season one—a character referred to in the script as "the most boring woman in the world." A small role, it was enough for her to stick out to the casting department, who hired her for various roles on other shows. "They went back and reviewed what I did on Murder House and they liked it," Porter says.

On Roanoke, Porter plays Lee Harris, a survivor of a possessed North Carolina home discovered to be in the same location as the disappeared Roanoke Colony. Her story is later told on the true-crime series within the series, My Roanoke Nightmare, with Bassett as Lee's re-enactment actor, Monet Tumusiime. Eventually, all of the survivors -- Lee, Shelby and Matt Miller (Lily Rabe and André Holland) -- and their "re-enactors" -- Monet, Audrey Tindall (Paulson) and Dominic Banks (Gooding) -- return to the house to find out the truth about the horror stories.

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Though she was initially hired for six episodes, Porter's character ultimately survived the show's slashing of its buzzy A-list actors to square off with Paulson in a Barbara Walters-like TV interview during the finale, which aired on Wednesday night. (Despite Audrey's onscreen death, Paulson returned as her Asylum character, Lana Winters, in a twist of fate that's only believable on American Horror Story.)

Assuming the penultimate episode was the last time she would get to work with Paulson, Porter offered her thanks to her onscreen partner. "And she said, 'Well, it's not over yet,'" Porter recalls, giving credit to Paulson, who recently took home an Emmy for her portrayal of Marcia Clark on Murphy's other FX anthology series, The People vs. O.J. Simpson: American Crime Story, for elevating her performance. "I really like that I had an opportunity to be involved with people where you could not phone it in. You have to be alert every second of the way -- and with Miss Paulson, every freaking second of the way, because she'll call you on it if she feels like you're not being genuine in the moment."

"I feel really good that she liked me. Because I think if she didn't like me, I could have been killed off in episode seven!" Porter jokes.

Adina Porter as Lee Harris on American Horror Story: Roanoke.

As dramatic as the final hour was, it didn't top the episode eight scenes Porter shared with Finn Wittrock, who briefly returned as Jether Polk to cannibalize Lee. Left alone together, Lee makes a drug-induced confession about killing her ex-husband before seducing Jether in order to escape. "I wanted the audience to question whether it was Lee wanting a moment of tenderness before the end -- any kind of tenderness, any kind of humanity," Porter says. "We wanted it to be like two human beings who are totally f**ked up but wanted some kind of connection."

Of course, Porter is no stranger to stealing scenes, as she has done in everything from True Blood to WGN America's slavery drama, Underground, only to be known as "that actor from that show." If it feels like Porter is finally getting some due after her notable recurring roles, she doesn't indulge it. In a response to a Twitter follower who asked what it was like to experience all this "major success" with AHS, the actress wrote, "I'll tell you when I feel like things are a 'major success.'"

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"I don't feel like I'm at this new level," she clarifies. "I don't because I think it takes away from the work. If I find out that the work is going well, so that means people want to talk to me or I might be able to get into another audition, all of that is fine and great. But I didn't know about the success of True Blood until season three."(Yet, she is happy to shed Lettie Mae's age and bad hair: "I walk into auditions and people are like, 'You don't like anything like her.' It's all about showing people that I'm not that old and redefining myself.")

"I'm a working actor and I want to stay a working actor and I want everybody happy," Porter says happily as she indulges in a celebratory glass of wine before boarding her flight.

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