According to Schnapp, the big action sequence looked incredibly real on set thanks to the practical effects that were used during filming. “We were running around the house, and all day we rehearsed the scene without the bullets [blanks] or any action of it,” Schnapp explained. “So on the first take, they did it with all the bullets and all the broken glass and the whole house down. From the first take, I felt this raw fear.”
Heaton clarified in an interview with GQ that the production used water round charges, which he describes as “like blank bullets, but they’re loud.” Brown also described the overwhelming nature of the stage setup, saying “there’s so much special effects and there’s air and there’s noise”, while adding to the atmosphere and pressure to make everything perfect. He praised the show’s “incredible security team” for making sure the scene felt safe, even as the turmoil and chaos allowed the actors access to real heightened emotions like the genre depicted. by Schnapp.
“For one actor at least, it makes it so much more real. It was really intense,” Heaton said of the production set-up, before making out her partner’s genuinely frightened facial expressions. “Noah is amazing,” he said. “The faces he has in this whole sequence, I think, were that he was really terrified. Without issue terrified.” Heaton also described the exhilarating, high-stakes filming process for the scene, which involved filming the shot with multiple performers, stunts and camera moves that had to line up, playing back footage on the monitors upstairs to look for imperfections, and tidy up the suite to start all over again.