SPOILER WARNING: This story discusses plot details for “Woman of the Hour,” now streaming on Netflix.

Netflix’s “Woman of the Hour” marks Anna Kendrick’s directorial debut, but that wasn’t the movie’s only breakthrough performance. Of all the featured victims, one young girl stands out in the ripped-from-the-headlines plot: Amy, a runaway teen, survived her encounter with the serial killer Rodney Alcala. Amid his murder spree, he was a contestant on “The Dating Game” in the 1970s.

Amy is played by Autumn Best, who makes her film debut with the pivotal role. She’s an alum of the CW series “The 4400,” but, believe it or not, she went into her audition with little to no hope of landing the part.

She was working as a barista at a coffee shop in Chicago when she learned about the opportunity. “I got the email, and I was like, there’s no way they’re gonna cast me in this Anna Kendrick movie — not only because it was Anna Kendrick, and she’s cool, but I only have one hand,” Best told Variety at the film’s premiere in Los Angeles on Oct. 10.

She’d been hoping to land a part in a feature-length drama, but best thought she would be the very last option envisioned for this movie. “Every time I get an audition for something that’s a real-life story, I immediately write it off,” she explained. “Because I convinced myself that no one would ever want to hire me to portray a real person who didn’t have a limb difference.”

Then, soon after sending over her audition tape, Best’s agent called to let her know Kendrick wanted to meet over Zoom to discuss the character. “I was working at the coffee shop at the time when I got the call. So I was like, ‘Let me step outside for a minute,’” Best said. “It was just so exciting!”

Best and Kendrick became “besties” during filming. “She can read my mind,” Best said about working with her director. “She could kind of just tell when I was, like, simply tired or cold, or just generally in my head.” (While introducing the movie at the premiere, Kendrick endearingly described Best as her “literal daughter.”)

Daniel Zovatto (who plays Alcala) also praised Best. “I just think she has a really bright future,” he said before recounting their experience filming a heart-wrenching and pulse-quickening sequence where Rodney attacks Amy while out in the desert.

“It was like six in the morning and it was fucking cold. The sand was literally ice. Autumn was wearing absolutely nothing, and that girl was ready to go. She was like, ‘Let’s do this,’” Zovatto said. “When you have a scene partner like that, it just makes it that much fun, because everyone’s on board. I loved working with that girl.”

Best said Kendrick comforted her while filming the challenging scene by wrapping her in blankets between takes and reassuring her about her performance. “She was very, very quick to just be like, ‘Hey, I see you,’” Best said. “Someone saying, ‘I see you,’ makes the day easier, because then you don’t feel like you’re pretending it’s not hard.”

Kendrick also shared her perspective. “It’s funny, because I certainly don’t think of myself as a naturally nurturing person,” she said. “But that wasn’t something I had to think about much, because I knew how much I was asking of the actors in the film. I’ve been in that position, and I know how much you’re offering yourself up.” Kendrick added: “Everybody treated the material with so much reverence, that that made me really emotional.”

In fact, all the women who portrayed Alcala’s victims shared how the supportive environment that Kendrick created on set was crucial for their success, especially during the more intense scenes.

“The moment my toughest moment was done, Anna popped out from behind the monitor with tears streaming down her face, and she was like, ‘Are you OK?’” said Kathryn Gallagher, who plays Charlie. She pointed out how rare that kind of energy is. “It just really shows you can have an incredibly warm and safe and comfortable set, with no sacrifice to making a brilliant movie. She set the bar really high.”

Nicolette Robinson (whose character Laura is an amalgamation of whistleblowers who tried to raise concerns about Alcala throughout the years) appreciated Kendrick’s vision, as well as her sensitivity.

“I knew we were in really great hands,” Robinson said, describing Kendrick as a dream to work with. “As actors, we don’t get a lot of validation. You don’t really know if what you’re doing that day is working. (But) she was so vocal and so supportive about reinforcing the positive.”

Kelley Jakle, who has known Kendrick since they co-starred in the “Pitch Perfect” movies, plays Sara, the first victim shown on screen. “There was one take where, before I even opened my eyes, I felt her arms around me in this big bear hug,” Jakle recalled. “It was just such a beautiful moment, both for our friendship and working with her as a director.”