The Americans ended its Emmy-nominated, six-season run this past May. But Keri Russell still jokes that she isn’t sure why creator Joe Weisberg, a former C.I.A. officer, cast her as the drama’s female lead. After all, Elizabeth Jennings is an ice-cold K.G.B. spy who has no qualms about killing countless men and bedding others for intel.

“I thought Elizabeth should be kind of Brigitte Nielsen—this cool, sexy spy lady,” Russell recently said, deadpanning. “I’m pretty much afraid to answer my phone. My friend Mandy [Foreman], who was on Felicity with me, used to call me and, after I’d say ‘Hello,’ she’d say, ‘Why do you sound so afraid? You know it’s me calling!’”

Russell has a point—her first acting role was on the Mickey Mouse Club. Before The Americans, Russell was best known for playing the wholesome title character on the WB’s college drama Felicity. When the show premiered in 1998, The New York Times noted in its review that Russell was “immensely likable” as a character “who struggles to stand up for herself.” Fifteen years later, playing Elizabeth Jennings in the series premiere of The Americans, Russell rammed the head of her rapist through a wall during a full-contact fight that left him bloody and struggling for breath.

“I rebelled in her, kind of, panther-like sub-fearlessness,” said Russell, who is nominated for her third Emmy for the performance. “Elizabeth is very much an adult to me—she dresses in silk shirts, her hair’s blown out, she has tough boots on, she’s not afraid to look everyone in the eye and live in the uncomfortable, weird silences. She’s not trying to make anyone feel better about anything. As a mother, she’s like, ‘You can take care of yourself, I’ll take care of myself.’ I loved that. She felt very adult to me, whereas I am not always. My six-year-old can get anything from me. She asks me twice for something and I’m like, ‘O.K., you can have it.’”

Unlike most depictions of women on television, Elizabeth is cold, contained, and an unapologetically bad mother. In her marriage, she is the emotional enigma, while husband Philip (Matthew Rhys) is more direct about his feelings. As such, Russell had to find ways to subtly telegraph her emotions between shifting aliases, allegiances, and appearances.

“All the disguises and spy stuff were such clever storytelling tools in showing different sides of Philip and Elizabeth—especially Elizabeth because she is so guarded,” said Russell. “I feel like through those disguises and those other covers she got to reveal little parts of herself that Elizabeth wouldn’t necessarily choose to reveal. . . . For someone who appears on the surface as so cold and unapproachable and un-relatable, I think we were really able to unravel that as the seasons went on. That being said, I loved how true Joe and [co-show-runner Joel Fields] kept the character, Elizabeth, until the very end. She didn’t all of a sudden start being the nice mom everyone wished she was. It kept her true, which is unusual for female characters.”

Elizabeth is able to overcome all kinds of obstacles and weapon-wielding enemies during the series’s run, yet, in the drama’s final season, it is her teenage daughter, Paige (Holly Taylor), who trips up the otherwise unflappable spy.

“I think it’s absolutely hilarious that her undoing was this 16-year-old,” laughed Russell. “And also, Paige’s rebellion was not smoking crack or fucking a million boys at school. It was her wanting to study the Bible and become Christian. That was too much for Elizabeth. She couldn’t handle it.”