Netflix's You Boss Says Season 4's Shocking Twist Was First Hatched 'A Couple of Seasons Ago'

[Warning: The following contains spoilers for You Season 4 Part 2. Read at your own risk!]

If you thought Joe Goldberg (Penn Badgley) was uncharacteristically dim in You Season 4 Part 1 — he was always one step behind the eat-the-rich killer Rhys Montrose (Ed Speleers) — it all made sense in Part 2 of the Netflix drama. In an absolutely shocking twist, the show revealed that Joe himself had been the killer all along: He was responsible for murdering Malcolm Harding (Stephen Hagan), Simon Soo (Aidan Cheng), and Gemma Greene-Graham (Eve Austin). The Rhys we saw? That was actually a version of the mayoral candidate created by Joe as a result of dissociating from his crimes. This unfortunately also means that Joe kidnapped Marienne (Tati Gabrielle), and she was trapped in none other than the man's signature cage.

You Season 4 Part 2's finale treated us to more twists, including one intricate plan devised by Marienne and Joe's star student Nadia (Amy Leigh-Hickman) to help the former escape. She succeeded in faking her death, and is so far the only one of Joe's lovers who has made it out alive without his knowledge. We talked to showrunner Sera Gamble about the ending, the future dynamic between Joe and Rhys, and of course, just what exactly Joe said to Phoebe (Tilly Keeper) in Sundry House in Part 1.

How did the twist to have Rhys be a part of Joe come about?
Sera Gamble: We started talking about having Joe completely dissociate and have a completely different, separate killer personality a couple of seasons ago. We started to talk about it in terms of, that's kind of a pinnacle of crazy. He's been unhinged since we met him, but we saw our job as — this is such a strange thing to say — but we wanted to earn this level of crazy for him.

What made this the right season to go for it?
Gamble: What happened with Love (Victoria Pedretti) and Henry, I think more than anything else. And also the fact that Marienne kind of breaks his brain a little bit. She is someone he can't lie to himself about as easily because she is so straightforward and honest and accountable for her life, and so clearly just wants to be a good mother. And that pushes a button in Joe. His need to be the man that he presented himself as to her, his need to prove her wrong in that first scene this season, it had some unintended consequences for him.

How would you describe Joe's mental health condition?
Gamble: I try to avoid psychiatric terminology. I know a lot of mental health professionals in life, I'm related to a few of them. And so I'm very well aware that what we do on a TV show is incredibly different than what people do in life to be diagnosed, and also that Joe's situation will not perfectly slot into the DSM. Honestly in the room, we call it "Pulling a Fight Club."

Joe and Kate are in a really good place at the end of this season. What exactly does she see in Joe? 
Gamble: He's a man who has done bad things, he wants to be better. I think what they see in each other is that they acknowledge their capacity to do harm, but also their shared desire to be good. So they kind of want to keep each other honest, which is a pretty hilarious statement for Joe.

Why did you want to have the finale end on such a positive note for Joe and Kate?
Gamble: We'd like to think of the end of this season as Joe's triumphant return home. And on some level, it's triumphant in every way. He's got a formidable, gorgeous, intelligent woman on his arm—although it could be argued that he's kind of on her arm. He has all of the wealth and power that he used to watch from afar when he lived in Brooklyn. And he shaved the beard, he took his name back, and so we thought of this as part one of a story with Kate. The season concerned itself so much with his relationship to this other killer, that there are a lot of ideas still left to play in a relationship story with Kate.

On the note of the other killer, I was so impressed by Ed Speleers' performance as Rhys. One of the last shots of the finale is of Joe looking into the window and seeing a reflection of Rhys. How does this reflect their dynamic moving forward? 
Gamble: Rhys' big pitch was integration, as he called it, the idea that when Joe stops rejecting the truth about himself it will be less necessary for a part of himself to split off entirely. It certainly seems at the end of the season like Rhys got what he wanted, which is to not have to stand there and scream and yell and laugh at Joe, but rather for Joe to embody both, which is good because he won't have to black out anymore.

Going back to Kate, does she suspect that Joe murdered her father? 
Gamble: We know that Kate has a nuanced understanding of killing because her dad, because of the world that she grew up in. And I think we made it clear in that scene [in the hospital] that there is in her mind, a type of murder that's justified or at least that can be forgiven if you really want to move forward. We intentionally left some of that stuff a little blurry, we intentionally cut away so that we weren't disclosing yet whether he went down the entire laundry list of every bad thing he's done or gave her a greatest hits that left some stuff out because that's the big question moving forward in their relationship. How honest was he really? And what does Kate think is going on with him? If we get to go and make a season in New York and see what happens with Kate and Joe, I think it's fair to say probably someone will die. And Kate will have to think about how that happened.

What inspired the decision to have Love and Beck (Elizabeth Lail) to return to confront Joe? 
Gamble: I always really enjoy it on TV shows where the Ghost of Christmas Past comes into the story for a minute. On just a purely — less about the storytelling more about being storytellers — we just loved the idea of seeing them again, so they could beat up on Joe a little bit. And then from a story perspective, when we got to this point in the season, we were like, well this is interesting because Joe is arguing with himself. And Rhys has taken Rhys' position, and Joe with his inner monologue has taken the other position. How are we going to move this conversation to the next place so Joe can make a decision? We need somebody else to come in to talk. We thought that the best candidates were the women he killed. They have a strong perspective on what it would take for him to change.

And regarding Marienne, why was it important to the story for her to escape? 
Gamble: We do a couple of happy endings at the end of every season. This is a character who has been so relentlessly through bad things. She walked into the story as someone who was really fighting against feeling like a victim or being a victim of a lot of genuinely terrible things in her life, and bad things that she had done. And the tone of her story has always been romantic, but in a really serious way. We just felt that the arc we wanted to see was one where she went from this place of, my ex is torturing me and I don't know how to take care of it so Joe steps in, to a place where she is on her own and finding cleverness and strength. I personally prefer her paired up with Nadia to Joe.

Since Nadia is now being framed for murder, what are the chances of Marienne leaving Juliet to come back and save Nadia?
Gamble: That is the crucial question because I think Marienne is very realistic about why they can't go to the police. If Joe knows she's alive, she feels he's capable of almost anything. So the need to protect her daughter, I think that comes first. But Nadia risked her life for Marienne, and they both know the truth about someone who's still out there. It's not a coincidence that in the writers' room, if somebody gets away from Joe we call it like, they live to fight another day — because maybe they will.

In the past, Joe has always framed an innocent dead person for his crimes. But at the end of this season, he frames Nadia for Eddie's death. Why did you change the formula?
Gamble: Joe thinks he's helping Nadia in some way. He has found a way for her to not only live but get to become the writer she's meant to be. I think he thinks he's helping her while also protecting himself. It could be argued, actually that the best move, the cleanest move for him to make as a murderer at that point in the story would be to kill her too. It is his genuine, you know he's got that mentorship streak with the young people. And he is proud of her as her teacher. I'm saying this all with a huge grain of salt, it's completely twisted. But in this case, he went a little softer on her, kind of the same as with Ellie (Jenna Ortega). So that's why she survives, but in prison and giving no interviews.

Can you tease whether we can see more of Nadia in the next season?
Gamble: First of all, now you know that even if people are dead, you can see them. But anyone who made it out, who knows the truth about Joe, is sort of fair game for future stories. This is not a story about a guy who commits perfect crimes, and then just kind of ghosts his way to the next city. He's messy, and this season was about a lot of stuff catching up with him and there's more stuff to catch up with him.

And finally, I have to ask: What did Joe say to Phoebe at Sundry House and how important is that to the story? 
Gamble: It's important to the story that we never tell now. It's lost to history, I am so curious to know what the actors said about it when they talked about it. But we decided we weren't going to ever say. Although I must say hours probably were spent in the room talking about exactly what it would be that would be so... It's not like the writers were like, whatever just leave it blank. But then we realized it was more fun to not tell.

Additional reporting by Megan Vick.

You Season 4 Part 2 is available to stream.