This article contains spoilers for episode 6 of season 2 of “Yellowjackets.”

Sophie Nellis keeps a close eye on what she eats. When choosing a restaurant for her 23rd birthday dinner last month, she chose an Italian place in Montreal that specializes in naturally leavened pizza, and commercial unleavened pies. Shop at Erewhon, the trendy health food store, when in Los Angeles. She loves organic buffalo cauliflower.

“I’ve been eating clean,” she said on a recent video call from her home in Montreal. “If it’s pizza, I just want it to be fresh ingredients, kind of farm-to-table, organic meat.”

However, Nellis’ character in Showtime’s psychological horror series “Yellowjackets” has a passion that isn’t so clean: human flesh. In the Season 2 premiere, her character, the teenage version of Shauna, snacks on her best friend Jackie’s ear. Later, she led a banquet feast of Jackie’s roasted corpse. (Don’t worry: the show used jackfruit and rice paper.)

Since the show’s opening scene, “Yellowjackets” has foreshadowed the high school football team’s slide into ritualistic racism and cannibalism. By this week’s episode, the sixth of the season, in which a terrified Shauna is forced to give birth in the wild, we already got a clear view of what it would be like to run out of food.

It’s a harrowing and haunting performance by Nélisse. She said she was walking around the stage during production with her prosthetic baby bump, and she knew the stakes were high. She cried a lot. But support from her team members made the experience easier.

“They would all come up to me before every day and say, ‘Hey, is there anything today we can help you with?'” A little tap on the shoulder, a hug. Fellow co-star Samantha Hanratty, who plays Teenage Misty, gave her a foot massage.

Nellis speaks digressively, with enthusiasm, swallowing all punctuation marks. She insists that she does not like being the center of attention. (“I still feel so shy and weird being introduced to a group,” she said.) But it might be time to get used to the spotlight. “Yellowjackets” has been renewed for a third season, and Showtime has delivered Nélisse to look at Amy in the lead actress category.

Growing up in Montreal, Nellie, like her character, didn’t have a typical upbringing. She began training competitively in gymnastics at age 4, some days working out as early as 7am, stopping to catch school and then back on the mat, putting in about 30 hours a week. Hoping to offset the costs of training, training, and competing abroad, she tried out for acting, auditioning for a Montreal agency.

“Maybe if I book anything,” she hopes at the time, “I’ll make pocket money.”

I did better than that. Like Shauna, she sometimes feels as though she has outgrown her youth. Her first click happened at the age of 9; Her first real kiss came at the age of 16, again on set. In 2012, she appeared in the Academy Award nominated Canadian film ‘Monsieur Lazhar’, which brought her international attention. When she was still a teenager, she landed a major role in the 2013 movie “The Book Thief”, she knew her elite training regimen would take months. I decided to commit to acting.

More roles followed. She said she wouldn’t change anything, but admits that the success came at the cost of some of her innocence.

“I never grew up with kids my age,” she said. “I’ve always been in a position with most adults, and I’ve always been told, ‘You’re so mature.'”

Deprived of their high school festivities and seasonal dances, the teenage girls in the “yellow vests” are also forced to grow up quickly. In the first season, Shauna plays the shy sidekick to the spunky team leader, Jackie (Ella Purnell). But after a battle at the end of the season drives Jackie into the woods, where she dies of hypothermia, Shauna must struggle to gain independence as she also struggles with guilt, starvation, and the demands of pregnancy.

In a sense, Shauna’s conversations with Jackie became more honest in Season 2. She happens to be with Jackie’s dead body.

Naturally, this camaraderie was the show’s entry point into cannibalism, said Ashley Lyle, who created “Yellowjackets” with her husband, Bart Nickerson.

“I want to be you; I want to destroy you. I love you; I hate you—it can all fuel this impulse you have,” said Lyle. “And it allowed us to introduce the actual act of cannibalism through a very specific character.”

As Nélisse watched Melanie Lynskey portray a clearly disturbed and traumatized adult version of Shauna, she initially tried to imitate Lynskey’s lip-biting antics but later rejected the approach after feeling untrue. (Nellis said she had an emotional breakdown after her blonde hair died.)

Nellis’ shell is more solid, Lenski insisted. She said that Nellis would push her to bring more aggression to the role. In the end, the two decide to do their best to connect with their characters rather than each other. Lynskey is impressed by Nélisse’s ability to lean into confrontation and create tension with the viewer – a stillness paired with a seething rage that gives the role so powerful.

“She’s a very sweet, sweet person, but she definitely has a more steel core than I do,” said Lynskey.

This steel was vital to the bloody, agonizing episode 6, in which Shauna is forced to give birth in the winter pod where all the teenage yellow jackets are stranded. Nellis had never given birth before, so she studied the stories, good and bad, of women who gave birth. Liz Garbus, who directed the episode, instructed Nellis to watch the hospital videos and birth scenes from “The Handmaid’s Tale,” a show Garbus helped direct, and from “Juno.”

Nellis spent days crying, sweating and screaming. In between every once in a while, she’d drink throat-laced tea with honey and lemon, trying to produce real tears behind her browned contacts. Garbus said she remembered calling out pieces on set, and the emotional impact of the heartbreaking moment — the baby doesn’t make it — on all involved.

“It wasn’t just Sophie crying — I was crying, and her classmates were crying,” Garbus said. “We have all felt deeply this horrific loss, the feeling of betrayal, the fear, the sadness and the anger.”

Nellis said she didn’t expect the baby to survive — she always prepares for the worst while filming “Yellowjackets,” she admitted.

Two months after the conclusion of the second winter season, the Nellis’ house is hit by a snowstorm—just in time for their 23rd birthday plans. The electricity was also cut off More than a million people in Quebecshe had to improvise, doing her hair and makeup at a friend’s mother’s office in order to get to the restaurant on time.

It wasn’t like starving in a snow-covered cabin, but it might have been a little close to comfort. Fortunately, no one resorted to cannibalism. But the experience made for some very memorable pizza.

“Right now, it’s a nightmare,” she said, “but I love stories like this because those are the ones you remember.”