Sophie Nélisse cannot shake this “Yellowjackets” plot line.

The Canadian actress, 25, recalled a particularly hard scene she filmed over her three-year reign on the Paramount+ psychological thriller as teen Shauna — and the popular shows that helped her through it.

During the Season 3 finale event in North Hollywood, California, on Thursday, April 13, Nélisse got candid about her most challenging scene in the series to date.

Warning: Spoilers below!

“I would say the birthing episode in Season 2 was definitely the most physically and emotionally demanding, and we shot that for a week,” Nélisse told The Post, referencing her pregnant character being forced to give birth in the wilderness without a doctor after her soccer team’s plane went down, leaving them stranded for more than a year.

To make matters worse, they were forced to reshoot parts of the daunting birth scene.

“We actually lost the footage and had to reshoot some of the footage,” Nélisse said.

When asked to explain how she was able to give such a flawless performance, the “Irena’s Vow” actress explained that she watched birthing videos from two popular TV series.

“There are great ones in ‘Handmaid’s Tale,’ even in like ‘House of Dragons,” noting that the characters in both shows are forced to give birth without the help of medical professionals.

Nélisse also noted that several important females in her life gave her guidance on what childbirth was really like.

She shared that she talked to her mom, the scene’s director (Liz Garbus), and her female friends helped “talk” her through the process.

Garbus — who also Season 4 finale of “The Handmaid’s Tale” — spoke to Variety regarding the research the pair did to prepare Nélisse for the birthing scene.

“I sent Sophie birthing videos and medical videos, and how it might be different in the wild. We looked at The Handmaid’s Tale, and the episode where Elisabeth Moss’ character gives birth all by herself. But we took it seriously, but we knew we wanted to have fun with that dream timeline,” she previously shared.

Nélisse told The Post that she felt the responsibility to “showcase the not-so-pretty sides sometimes of miscarriages that we don’t necessarily shed enough light on.”

In Episode 6 of Season 2, titled “Qui,” teen Shauna goes into labor and only has the help of her teammates to get her through. It’s a disturbing scene, full of chaos, a dream sequence, and then, the sad reality that her baby boy did not make it.

“Yellowjackets” fans have watched teen Shauna’s bitterness intensify after losing her son and her best friend, Jackie Taylor, who froze to death in the snow, so the team ate her to survive.

Season 3 showed some of her stranded teammates challenging her as she bulldozed her way into the role of their leader.

Nélisse, however, is embracing her character’s darkness.

“I view her as a villain, but I love rooting for the villain,” the actress told The Post. “I think she’s so layered, and because we’ve had these two previous seasons that the showrunners have so beautifully crafted, I think it still makes me empathetic towards Shauna because you understand why she is the way she is, having undergone so much trauma, so much loss.

“And to be just a teenage girl in the wilderness with no tools, no healthy way to let out your emotions or to understand your emotions, I can understand how someone would feel the need to lash out that way,” she continued. “So, I feel for her, and I think she’s doing the best she can. I’m not saying her actions are forgivable, but they’re understandable.” 

When asked how she personally unwinds after a grueling day at work, Nélisse shared that she spends time with her “Yellowjackets” co-star and roommate, Courtney Eaton.

The star lives with Eaton (who plays teen Lottie) while they are shooting the psychological thriller.

“That’s been really helpful just to have someone to banter with on the way back home and to just vent [with],” she said of their friendship. “We often will just watch our favorite shows, and we’ll walk her dog on weekends, and we love to cook, so we’ve been doing a lot of that.” 

The finale of Season 3 was available to stream starting on Friday, April 11, and the title “Full Circle” couldn’t have been more perfect.

The 10-episode series was a bloodbath, with viewers seeing many of the original stars being savagely knocked off one at a time.

The brutal deaths that no one saw coming weren’t just hard on the fans, either.

Tawny Cypress (adult Tai) broke down in tears over one character’s death, which she found particularly hard to accept both on and off the screen.

Christina Ricci also shared her sorrows about seeing many of her core cast members go.

Oscar-winner Hilary Swank joined the cast in Season 3, and she also broke down the diabolical kill scene that made Cypress so emotional.

“Yellowjackets” Season 3 is available to stream on Paramount+ with Showtime.