(Spoiler alert: Do not read on unless you’ve watched “Black Mirror”s Season 4 episode “USS Callister.”)

You may now think of “USS Callister” as one of the greatest “Black Mirror” episodes of all time. But when star Cristin Milioti first auditioned for the compelling Season 4 episode that included a brutal deconstruction of toxic masculinity, workplace sexual harassment and cyber-bullying, she hadn’t the faintest idea what it was about — let alone how badass a character she’d be playing.

“I was sent like a couple pages of the script and I auditioned for them,” Milioti, who plays Nanette in the “Star Trek” homage episode of the Netflix anthology series, told TheWrap. “And I’d seen one episode of the show and loved it. I watched the episode right before I went in and I found out a couple days later I got the part. I never met anyone.”

“Callister” takes place in a virtual reality game based on an in-universe “Star Trek”-esque TV series called “Space Fleet.” But the titular ship’s crew are actually the cloned consciousnesses of several co-workers being held captive by resentful company executive Robert Daly (Jesse Plemons), who serves as their “captain.” Including Nanette — the new object of Daly’s obsessions.

Also Read: 'Black Mirror': 14 Times Season 4 Referenced Other 'Black Mirror' Episodes

“I didn’t even know what my role was. They gave me two scenes. I remember saying, ‘Well, I can’t even — I don’t even know what I’m doing!”‘ Milioti said, laughing. “But I could tell from reading it the writing was so good. But I had no idea. I couldn’t tell what any of it meant or who I was playing at all. I just knew I loved what I read. So then, when I actually read the script, I was so blown away.”

Though the audition process may have been a crazy experience, it paid off when Milioti was handed the role of a lifetime. She steals the show with a performance that included this now infamous line, delivered when she realizes that Daly has eliminated the characters’ genitalia inside the game: “Stealing my p—y is a red f—ing line!”

Also Read: 'Black Mirror' Star Cristin Milioti on Fighting the Man and the 'Red F-ing Line' in 'USS Callister'

“I had such an incredible time on this job,” Milioti said. “This is not just saying this. It was a dream job and it was a dream all around. I think it was incredible to be able to show a story like this. I’m kind of getting over excited thinking about everyone seeing it.”

And it turns out she had every right to be psyched, as the episode has fast become many viewers’ favorite from Season 4 — if not the entire series.

“Black Mirror” Season 4 is available for streaming on Netflix as of Dec. 29.