SPOILER ALERT: Do not read if you have not yet watched “Unknown Caller,” the fifth episode of the third season of “The Handmaid’s Tale.”

The second season of “The Handmaid’s Tale” ended with Serena Joy (Yvonne Strahovski) truly becoming a mother as well as seemingly picking a side in the fight against the misogynistic regime — by putting her child first and letting her leave Gilead. But as the third season of the dystopian drama has quickly proven, impulsive actions are often out of character, and they are not easy to recover from.

“I always thought that Nichole was her one shining light — the thing that was going to get her through her life — and without it she is nothing,” Strahovski tells Variety. “It’s so layered and complicated, and it takes her a minute to realize, as I think it would with anyone in a heightened emotional state, that she’s going through trauma.”

Season 3 started with Serena feeling the loss of baby Nichole (née Holly). In fact she was so unsure of how to go on with life without her, she was reckless and suicidal: First she burned down the Waterford home, reluctant to follow June (Elisabeth Moss) out to safety, and then she walked into the ocean, wallowing deeper in her grief.

“I do think she is a blamer and that she blames June for parts of it. She blames the Commander, in that he forced her to make that choice because of the conditions at home and because of what he did to Serena with chopping off her finger and beating her,” Strahovski says. “But I do think she’s aware of her own choice in the decision, too. I think she is mad at herself, as well as mad at June’s influence.”

A character as strong as Serena couldn’t be down for the count for long, and soon enough the wheels started turning for her to manipulate her way back to Nichole.

In the fifth episode, “Unknown Caller,” Serena managed to convince both Fred (Joseph Fiennes) and June to let her travel to Canada to see the baby. With June, she preyed upon their shared bond over the baby so she would tell her husband Luke (O-T Fagbenle) to bring the baby to the airport to meet Serena, telling her she needed closure and a real chance to say good-bye. Of course, once she spent some time holding Nichole, she wasn’t so ready to let her go, and Serena came back to Gilead with a new plan: to tell the world the baby had been kidnapped out of Gilead and to plead for Canada to return her home.

“That was definitely something for me to overcome when Bruce told me that that was what was going to happen in Season 3,” Strahovski admits. “I remember being kind of astonished that they were going to do that because I had thought she had really made the right decision [at the end of Season 2], and that Season 2 was really about Serena learning what it was to be a true mother. Unfortunately what was best for her child was the worst thing for her, but she did it anyway, and she learned what that ultimate love and sacrifice meant.”

Strahovski shares that when she first learned the lengths that Serena and Fred would go to bring Nichole back to Gilead, she considered it “crazy” that she would go “backwards and against what she had learned.” But the more she sat with the story developments, the more she realized that “of course that would be something that Serena would do.”

“Serena’s the type of person to sit with that and think about exactly how she would go about it, if she was going to do something like that. I think she works things out pretty carefully, which is why I think she’s also pulling back on her decision to give the baby away now. That was not a planned thing — that was not something she manipulated over many nights — it was something done in the moment,” she explains.

Additionally, Strahovski notes, there is a battle brewing between Serena’s heart and mind: “In her mind I think she understands she made the right choice [to let Nichole go], but I think her heart is bleeding so badly and she cannot control her own emotions that it ends up winning. And she gets back to manipulating things around so she can have the outcome that she wants.”

Strahovski herself was pregnant while filming the second season of “The Handmaid’s Tale,” but she tried greatly to separate her pregnancy from what she had to do on-screen then. After giving birth to her son, though, Strahovski says being a mother has inspired her work in the third season. “I just found that using all of those emotions of real life was very helpful,” she says. “When you’re so emotionally invested in a child, and you really believe it is your child as Serena does, you will do anything.”

Filming the reunion scene with Nichole became one of Strahovski’s “top 3” favorite scenes in the whole series thus far. The show’s director of photography Colin Watkinson made his directorial debut with “Unknown Caller,” and Strahovski recalls sitting down with him and Fagbenle to map out the machinations of the scene early, so that “when we got there we could be in our emotional space” to more fully explore the scene.

Strahovski enjoyed getting to find a rhythm with Fagbenle as actors. “As a fan of the show and watching everybody else’s work, I’m always so gripped. So when I read the script and characters like Luke and Serena get to interact, worlds collide, and that’s so exciting to me,” she says. “There’s that one line that I just find so fascinating, where she says to Luke, ‘This isn’t about biology.’ Because Luke is also not the biological [parent], and I just find that to be so incredibly fascinating in the battle for this child, in this crazy, political circumstance. It’s pretty astounding and complicated.”

But she was also glad to work in a space that had a different vibe than Gilead — one with the openness, modern and naturally lit space of the airport, full of extras wearing regular clothes and Strahovski also, for a change, out of her usual teal wife’s frock. Although the scene was still laced with manipulation on Serena’s part, and included her threatening Luke, she, too, got to be lighter as she embraced the baby for a bit. “It’s rare to see Serena experience something so pure,” Strahovski says.

The reunion becomes “so overwhelming for her, with all of the love and all of the feels she has for that one child,” Strahovski adds, and as Serena begins to put “the pieces of her right mind back together, unfortunately her right mind isn’t one that’s full of integrity.” So while she hears Mark’s (Sam Jaeger) offer to help her stay in Canada, she keeps that tucked in the back of her mind, choosing instead to focus on “manipulating herself” into thinking she can survive in Gilead if she just as the baby back.

“I think she’s very good at being in denial of things,” Strahovski says. “She comes back to the dark side, in a way. She goes back to Fred and allows for her faith to be put in him and to see if his plan will work and if he’s really invested in her in a way that he says he’s going to be. As she sits in this trauma I think she probably feels it’s the only option, and it gives her a chance to fall back into the old Serena, which is, ‘If I could just have Nichole, then everything’s OK.’ It gives her that hope again, despite everything around her. And that takes us back to the whole survival in Gilead; you watch all of these characters make choices for survival, whether that means making a choice of integrity or not. And she’s definitely somebody who’s still surviving.”

“The Handmaid’s Tale” Season 3 streams new episodes Wednesdays on Hulu.