Twenty minutes into a conversation with a small room of critics following an early screening of "Janet(s)" — the midseason finale of The Good Place — series creator Mike Schur cuts himself off in the middle of an answer. "You can tell, by the way, how much we've been dying to talk about this, because you guys have asked, like, one question."

And yes: Even for a show that prides itself on nutty twists, this episode was a big one, and there is a lot to talk about. (Consider this your requisite spoiler alert.)

A quick rundown of the major moments The Good Place just crammed into a single episode:

  • Chidi realizes he's in love with Eleanor
  • Tahani and Jason learn that Janet used to be married to Jason, and that Janet is still in love with him
  • Michael learns that no one — no one — has made it into the Good Place in 521 years ...
  • ... until now, because Michael successfully smuggles the four humans into the actual Good Place — as the episode ends (to the audible groan of me, as I realize this cliffhanger won't be resolved until next year)

If that wasn't enough, The Good Place unspools all these twists in an episode largely centered on a grab-bag of performances from a single actress: D'Arcy Carden, who plays no fewer than six different characters in the episode (including a new Janet, Neutral Janet, who falls at the exact nexus between Good Janet and Bad Janet). She was even asked to convincingly embody nearly all of The Good Place's main characters.

Let's back up for a second. In the previous episode of The Good Place, Janet rescued Eleanor, Chidi, Tahani, and Jason by bringing them into her "void" — a white liminal space located somewhere inside her (not-a-robot) programming.

But this week, we learn that the journey came with an unexpected side effect: The four humans have been physically transformed into Janets. Which meant, of course, that D'Arcy Carden was tasked with playing Eleanor (Kristen Bell), Chidi (William Jackson Harper), Tahani (Jameela Jamil), and Jason (Manny Jacinto), as well as the Janet she usually plays. Relying on visual effects, trick photography, and stand-ins, much of the episode is just Carden in a blank white room, acting opposite herself (and doing uncanny impersonations of her four costars). "It was a form of psychological torture," jokes Schur. "I went crazy," confirms Carden.

How did it all come together? The show's writers had been kicking around this idea for at least a year, but "Janet(s)" posed a considerable challenge from both a technical standpoint and a performing standpoint. "We were like, 'Can this be done?' Well, Orphan Black did it like, a thousand times," recalls Schur. "That's what I kept thinking. I remember the scene in Orphan Black when all of the clones finally meet each other, and [star Tatiana Maslany] was just handing herself things, and talking to herself, and, like, had her arm around herself and stuff. That show gave us a boost at the beginning, when we were debating whether or not to try to pull it off."

Carden first learned about the acting feat she'd be required to pull off in March, which gave her months to prepare before a five-and-a-half day shoot in July. "It's not necessarily hard to play five different characters, but it is really hard to play five different well-established characters that I've known for years now," says Carden. "It's, like, a different thing than just making up five new ones. We were really figuring out if we wanted to do impressions of them, or just a hint of them. We didn't want it to be like SNL sketch characters. We didn't want it to be over the top."

To help Carden capture the nuances of her co-stars' performances, the episode's scenes were filmed with Bell, Harper, Jamil, and Jacinto playing their usual roles. Carden then built her impressions — everything from accent and inflections to the subtleties of body language — by studying that footage. "I watched the video a lot," she says. "I also voice-recorded our table read, and I didn't listen to music for like a month. I listened to that. There was one day I was listening to it cranked up in my car, driving down Sunset, and I see Will Harper walking down the street. So I pulled over, rolled down my window, and I just blasted. And it was his voice. And he went, "Oh no. You're losing your mind.'"

And for the swoony climactic kiss between Eleanor and Chidi — which brings Eleanor, who has been spiraling through dozens of avatars, back to herself again — the visual effects required a particularly strange performance. "There was a long pole ... with a literal pair of lips. Plastic lips," says Carden. "It was exactly at my lip height, and it was on, like, a Lazy Susan. It was controlled by some dude. But it was a pole, not a body. So I had to, like ... hug air, and kiss these lips. And then we would start spinning. And I couldn't smile, or laugh. [...] And then I had to kiss Kristen. But it had to match exactly the head tilt. Every inch of us had to match. We just had to sort of, like, be pressed against each other. In a very not sexy way at all. 'Now move your hair, and your mouth.' It was like surgery, almost."

Meanwhile, the B-story in "Janet(s)" follows Michael as he travels to meet the Accountant, who is responsible for compiling and calculating the scores that determine whether someone is sent to the Good Place or the Bad Place. The Accountant is played by Stephen Merchant, who co-created the BBC's The Office. "I knew him from The Office, a little bit, and it was very funny to try to explain the character he would be playing," says Schur. "'So, here's the episode. Wait, hang on, let me back up. Here's four episodes earlier. No.' And I literally had to go back to the pilot. And I had to pitch him the pilot, and the Season One twist, and then a bunch of stuff from Season Two, and then move through Season Three really quickly. It took, like, 45 minutes on the phone. And then he was like, 'Alright, sounds good.'" (The introduction of the Accountant also offers a wink to eagle-eyed fans of The Office: The Accountant carries a coffee mug that reads "EXISTENCE'S BEST BOSS" — a wink at the "WORLD'S BEST BOSS" mug carried by Michael Scott on NBC's The Office.)

Michael's quest ends with the startling revelation that it's been 521 years since a human being has been granted entrance to the Good Place. It's a number that led to a spirited discussion in the show's writers' room. "We made a list of, like, a dozen people where it was like, 'This has got to be a no-brainer,'" says Schur. "Lincoln was one. Harriet Tubman, Jonas Salk. It's people who did something good that affected an enormous number of people, right? But it's funny, because when you play that game, you go, 'Well, this person has to be in.' And then you go, 'Oh, no, no. They don't.' Thomas Jefferson? No. George Washington? No. And that is what gave us a little bit of wind in our sails for this idea. Go try to find the Incontrovertibly Great Person in history, who never did anything [wrong]. Basically anyone pre-Antebellum is screwed, in America. [...] We chose roughly 521 years because we sort of figured that once exploration moved from Western Europe and moved across the ocean ... basically, that was the last moment. After that moment, it was conceptually impossible for anyone to get in, via the criteria we've set up."

And if you're wondering when you'll find out which person was actually good enough to clear that Good Place bar 521 years before the events of "Janet(s)," Schur has a teaser that'll whet your appetite until show returns next year. "The question of why nobody has gotten in [to the Good Place] in the last 521 years will be answered in the next episode."