As with every “Scandal” interview: Spoilers ahead.

“Cyrus, I’ve committed a sin.”

These five words changed the course of “Scandal’s” Vice President Sally Langston forever and likely earned Kate Burton her well-deserved third Emmy nomination (this time as an outstanding guest actress in a drama series).

“I was sitting in my kitchen in New York City where I had been spending the month of July and got a call from my manager, Larry Taub,” Burton says. “I realized how early in was in L.A. and I just suddenly went, Oh wait a minute…’Cause I sort of knew, I remembered from ‘Grey’s Anatomy’ when [the nominations] kind of come out. He said, ‘Congratulations,’ and I went, ‘Oh…my…god.’ ”

Though it’s not a new feeling for Burton—who was nominated twice for her performance as Ellis Grey on Shonda Rhimes’ “Grey’s Anatomy”—it hasn’t lost its je ne sai quoi.

“I was thrilled for so many different reasons,” she says. “I feel so blessed to have this writer, Shonda Rhimes, write these two amazing characters and I’ve gotten to play both of them. And the fact that I’m 56 years old, and I’m not on social media. And I really thought, I don’t know if I have a chance because I don’t tweet, I’m not on Facebook, I don’t have a following.

“My life is so complicated, the thought of tweeting is more than I can handle,” she adds, laughing.

But even if she can’t tweet, she can play the murderous and politically dedicated Sally Langston.

On what makes Sally tick.
Now that Burton’s played Sally for three season, she says, “When you get an opportunity to play a character as much as I’ve gotten to play Sally, it actually becomes like breathing.”

And it’s this knowing her character inside and out that makes Burton so successful as the vice president. “She’s gone from being this very ambitious, political, very devout person…. Whenever you play a character that’s perceived in any kind of way as a villain, you have to know what it is that makes them tick, and what makes her tick is the truly blinding—absolutely blinding—devotion to her faith. And this is the thing that gets her through. And the thing that’s absolutely devastating to her finally is that she’s being punished by God for killing her husband,” she says.

“And of course, then there’s moral corruption of the president [Tony Goldwyn, who Burton says she’s known since they were in their early 20s]. She just thinks he’s absolutely morally corrupt and at the end of the day she believes that it is literally her religious mission to drive him out of the White House,” Burton explains. “So it’s this see-saw thing of the devout, God-fearing woman and the blindly ambitious political candidate.”

On Sally’s southern accent.
Sally’s accent makes Rhimes’ writing even more fun, according to Burton—(the writing co-star Joe Morton described as “delicious,” when we spoke to him a few months ago)—but she didn’t prep for it as much as you’d think.

“We went to shoot the very first day three years ago and I got to the set and Shonda was there, and normally she’s never there. And there she was and I said, ‘OK, Sally Langston. Is there anything you want to tell me?’ and literally we were about to shoot the scene, and she said, ‘She’s southern,’ ” recalls Burton.

“And I don’t know how I did…I don’t know what accent I’m doing but I just had to go! So I don’t think about it too much—just let it kind of rip. And it was always great when I was really having my haranguing time, […á la ‘Yum, yum, crispy piggy, yum, yum.’]” she says.

On getting her career started later in life.
“Things started to really happen for me in my 40s in the theater and I started to get Tony nominations when I was about 42,” Burton says, “and I was really so thrilled that I got an opportunity in each decade to take on something new. In my 40s I got to play amazing roles in theater—[the title role in “Hedda Gabler” and Constance Middleton in “The Constant Wife” to name a few]—and then I had always done TV but ‘Grey’s Anatomy’ happened. And I knew as soon as we were doing the scenes, [I thought,] This feels different; This feels really special and original and I don’t know why.”

But Burton, now 56 and a three-time Tony nominee and three-time Emmy nominee, couldn’t be happier with her career timeline. “It’s great when it happens to you a little bit later because, honestly, when you’re young you’re dealing with so much stuff—you’re trying to start a family; you’re trying to have a career. Ambition is an interesting thing,” she says.

Though her “Scandal” future is unclear, Burton will return (from the dead) to “Grey’s Anatomy” for Season 11, reprising Ellis Grey in flashbacks.