I Genuinely Can't Watch These 15 Acting Pairs The Same Way Again After Finding Out What Happened During Their Chemistry Tests

"It spoke volumes about their potential relationship," Ronald added when looking back at the chemistry between Sam and Cait during their chemistry test. 

Talking about meeting Sam for the first time and their chemistry, Caitríona told The Wrap, "It was just quite instantaneous, in a sense. When I first met Sam at our chemistry test ... he was just the nicest guy and he just put me at ease. I was a little nervous and he's just that kind of solid, grounded guy."

Simone did say the chemistry read was "bizarre" because it involved her and Jonathan in a room together while they video chatted with Shondaland producers.

Thinking back to their chemistry test, Simone told Extra, "Johnny is an incredible actor. He's so generous, and [he] was just so easy to work with. So effortless."

In another interview with Extra, Corey said he had his first chemistry test with India in 2022. He said, "We worked well before we knew anything about each other. And then, like, I don't think it's necessary, but being friends helps. That came pretty naturally."

Corey added after doing the scene where their characters meet during the chemistry read, they also performed the scene at the end of Episode 1. Corey said it was exciting because they were able to perform the scenes a few different ways.

He told Deadline, "It was before the chemistry read that I was then told, ‘You’re gonna meet Hannah Dodd, who’s playing Francesca, and you’re reading for the character of John Stirling, Earl of Kilmartin.’ I didn’t know if he was a book character."

Victor said he then Googled John's name and found out what happened to him in the book series.

"As soon as I went in...there was just a really chilled energy, and we went over [the scene] loads of times," Jodie explained. "Sandra was like, 'Do you want to do it again? Is there anything you want to change?' She's very patient and just very present."

Meanwhile, Sandra recalled meeting Jodie, telling The Graham Norton Show, "I knew that we had good chemistry. I could just tell. It was the way that we were listening together and the way that I could feel how she was receiving anything that I was giving to her, and she would react. I think chemistry, in some ways, between actors is about listening."

Lenny continued, saying, "And then you know you've got this alive energy that feels correct for the book and the adaptation, and at that point you can go, 'Great! We can really make it now.'"

Recalling her chemistry test with Andy, Melissa told BuzzFeed, "I remember my test with Andy — even the dynamic was different. [Amy] was always trying to top him, and there was a real competitiveness with them."

Joe did a chemistry read with two different Nicks, while Kit did one with two different Charlies. "But we found one another, Joe and I, we found one another," Kit added in an interview with Entertainment Weekly.

Looking back on the various chemistry reads she had to do alongside potential actors for Derek, Ellen told Variety that Rob Lowe was "supposed to come to the screen test" but didn't show up. Meanwhile, Isaiah Washington, who went on to play Preston Burke, was a frontrunner and someone creator Shonda Rhimes liked for the role. 

Lola was a freshman at Carnegie Mellon when she got the audition and told E! News that she was "intimidated" by Chris the first time they met. Meanwhile, Chris told Harper's Bazaar that he was feeling "really nervous" during the Zoom chemistry read. 

Gillian added, "For some reason, there was something tangible and palpable that existed between us right then." 

Meanwhile, David told Deadline that he and Gillian "never worked" on their chemistry. It was something that came naturally. He explained, "It's really a mutual respect and enjoyment of acting with one another. What exists in the writing, as well, is that these two people are true partners and they complete one another intellectually and emotionally."

Mads added in an interview with Vulture that once he read alongside Hugh, it was the first time he felt comfortable during the audition process. He said, "I was really reluctant to do that. I don’t like castings. Nobody likes castings."

"That was one of the first things I asked when I found out I got it: 'Who is Fitz?,'" Elizabeth recalled, and the producers told her right away that Iain had booked the role. She added that the producers chose Elizabeth and Iain for the roles of Simmons and Fitz "at the same time."

Danielle recalled in an interview with BuzzFeed alongside Calahan, "When Calahan walked in, and it was the last of the day, and I was like, Oh, that's who it is. It was like, you didn't know what you were looking for until it walked in the door, and it clicked."

She told Collider, "It was an amazing chemistry and a security, from day one, from the first second." After her first chemistry test, Rebecca said she was "called back four times" before she landed the role, which ultimately was her first English-speaking TV role. 

Speaking about working with Rebecca during the casting process, Max told the Boston Globe, "She not only had the power, the intelligence, and the sexuality required, but she could walk that political line so delicately. She had all the skill that Elizabeth had to have to survive the court. It was clear from that moment that she was the person to play the role."