The sequence took six weeks of rehearsals and it's all real. But Blunt wasn't in the rehearsals and when she finally sat down in the car, she didn't know anything that was about to happen – to keep the reactions as authentic as possible.
"I realised as I was explaining to her all the things that are going to happen, like 'You're going to hit this pedestrian and then these cars are going to cut you off, and then a bus is going to come at you at 40 miles per hour'," Krasinski told Live with Kelly and Ryan.
"That's all happening to her. And I realised, 'oh my god, I just put my marriage on the line, I might end my marriage in this shot'."
Krasinski was, of course, joking, but if Blunt's character's reaction in the scene – absolute terror – is what Blunt was actually feeling, then he really put his wife and leading star through the wringer.
It's a good thing then that he can make up for it by singing her praises the world over.
He told a virtual live Q&A session following Australian preview screenings for A Quiet Place Part II: "Everybody was wondering how it would go working with your spouse and so were we, we were very excited to see how that would go and by excited, I mean terrified.
"On the first movie, I found the best collaborator of my entire life. She's not only the best actress but she's someone who puts everyone at ease because she's so unbelievably prepared, unbelievably professional and cares so deeply about the entire process, the whole system, so it was almost like she was a producer on the movie.
"There were days when she wasn't shooting, and she'd still come to set and she'd still see the shots and cheer us on.
"She is without a doubt, not only the best actress I have or will work with, but she's the greatest collaborator I've ever had."
It's been a long wait for A Quiet Place Part II, which was originally scheduled to be released in March 2020. Its stars had already done their jobs promoting it, it had a glitzy premiere, and all the marketing posters were up around the world.
Then the pandemic hit, and it was one of the first movies to be yanked.
Except for the flashback scene that opens it, A Quiet Place Part II picks up moments after the first film wrapped up, with the Abbott family still trying to survive on an Earth that's overrun by alien monsters whose razor-sharp hearing and razor-sharp teeth have decimated the human population.
With its nail-biting tension and visceral effects, it's a movie that demanded a cinema experience, which, 14 months later, is about the eventuate for Krasinski, Blunt and all their fans.
