Scarlett Johansson and Florence Pugh’s chemistry in Black Widow is so strong that you’d be forgiven for thinking the Marvel Studios action-spy thriller was just the latest in a long line of collaborations. Widow, on the other hand, marks Johansson’s ninth appearance in the MCU and introduces fans to Pugh’s character, Yelena Belova, who has a sad past with Natasha Romanoff. Since Natasha sacrificed her life in 2019’s Avengers: Endgame, Johansson has hinted that Widow — which takes place seven years before Endgame — will most likely be her final appearance as the role she’s played since 2010’s Iron Man 2.

But it appears that a lot of hard work went into their on-screen connection, courtesy of Cate Shortland, the director of the Marvel film, who left no stone unturned to ensure the two costars got to bond.

“Cate Shortland brought in someone who could coach us through some bonding and trust exercises,” Johansson stated in a recent interview with The Hollywood Reporter. “And that was kind of goofy and fun. But the real bonding happened on the first or second day of Florence’s work when we immediately slammed each other into door frames and cabinets.”

“We bonded over a headlock,” Johansson says.

Nothing creates sibling ties quite like wrestling, which Pugh elaborated on:

“The moment where I totally died was when we were doing a scene and Scarlett put her hand in my armpit. [Laughs.] And I just died because I knew how sweaty it was. So Scarlett looked at me and went, “That’s a sweaty pit.” I was like, “Oh, no! That’s it. It’s over. R.I.P. Scarlett Johansson tested my sweat.” [Laughs.]”

“It’s a tough job, but somebody’s gotta do it,” she continued.

“The physical work is so grueling, and you can really burn out on that stuff,” Johansson tells The Hollywood Reporter. “I did say to Florence in the beginning that this is a long job. And selling things — the emotional grit behind it — is a much more valuable way to spend your time than actually trying to be a professional athlete. The whole stunt department are incredible athletes, and you’re never going to reach their 16 years of professionalism, or whatever, in four weeks. So that’s the one piece of advice that I wish I had gotten, which, eventually, Sam Jackson gave me and now I pass through myself to Florence. ‘Don’t kill yourself, kid!’ Sam Jackson said to me; it was something like that. So I took his advice.”

The two actors’ chemistry is palpable on screen, as they maintain a playful sibling rivalry throughout the film.

Early Black Widow previews depict a complex relationship, with Yelena and Natasha engaging in hand-to-hand fighting before having a family meal with David Harbour’s Red Guardian and Rachel Weisz’s Melina Vostokoff. While the early battle sequences suggest an antagonistic relationship, we all know Natasha has a habit of pointing guns at even her closest pals. And there are several reasons to assume her connection with Yelena is based on love.

“I remember the stunt team was like, ‘So Florence, what are we going to do about your pose?’” Pugh recalls. “And I was like, ‘Oh God, I have to think about a pose!?’ And they were like, ‘Yeah, because you know Scarlett’s is this.’ And I was like, ‘I know! Who would actually land like that? That’s ridiculous!’ And they were like, ‘Well, yeah. If she actually landed like that, she would have broken her spine.’ And I remember I was just teasing [Scarlett] for it, and Eric [Pearson], the writer, was on set and was like, ‘Yep, that’s going in the script!’”

Insider’s Kirsten Acuna wrote in her review of the film: “If you’re not already a fan of Pugh, you will be by the end of ‘Black Widow.’ Yelena’s a firecracker with great one-liners and jabs at her ‘older sister.'”

Natasha and Yelena have a history together, having trained in the Red Room, a top-secret Soviet training facility that haunts Natasha’s conscience. Natasha’s new family has been an important part of her journey, and it is one of the reasons she is able to confront her history as a Soviet spy.