“U.S.S. Callister,” the Star Trek riff that kicks off the latest season of Black Mirror, is full of astounding sequences. The episode switches back and forth between an office and a Star Trek-like video game simulation called Space Fleet that Robert Daly (Jesse Plemons) runs to inflict torture on the co-workers that bully him. At one point, Walton (Jimmi Simpson) is explaining the rules of the simulation to new recruit Nanette Cole (Cristin Milioti). Walton literally pulls down his pants to demonstrate that their avatars don’t have genitals. So when Simpson stopped by PeopleTV’s Couch Surfing, host Lola Ogunnaike had to bring up that scene.
Simpson explained that molding his genitals for the plaster used in that scene was one of the first things he did upon arriving in London to start filming for Black Mirror.
“I arrived in London, and I was driven off a country road for an hour and a half to a little shack, where a lovely British man molded my genitals and thighs and found a place to tuck everything away, and prepped me for that,” Simpson said. “That was my intro to England, and Black Mirror: A small man putting plaster of Paris on my junk.”
Watch the full clip above.