[Warning: This story contains spoilers from the season nine finale of Curb Your Enthusiasm, "Fatwa!"]

Curb Your Enthusiasm's comeback season began and ended with Larry David singing the words to Mary Poppins' "A Spoonful of Sugar."

In the 10 episodes between that first and final scene, the TV character had a death sentence placed on him by Iran's Ayatollah, lost a steady-ish girlfriend (played by Lauren Graham) and poured his heart and soul into dream show Fatwa! The Musical, only to have it go up in blue-colored smoke in a Hamilton-style duel gone wrong with its star, Lin-Manuel Miranda, one week before opening night. Despite all of those major life events, coupled with a litany of other petty and selfish shenanigans, the season nine finale proved that in the world of Larry David, nothing has changed.

But then, mid-skip, Larry is confronted by an Iranian man who didn't get the Muftis' message that the fatwa on Larry's life had been revoked. While being chased by a potential assassin, Larry screams, "Fatwa's over! Didn't they tell you? Don't shoot! They called it off!" and the screen fades to black.

"I always say every season is the last season of Curb," executive producer Jeff Schaffer tells The Hollywood Reporter of the fate of the series (despite hopeful hints from David, HBO has yet to announce a tenth season). With the series' future up in the air, Schaffer explains of the ending, "All that work, and Larry has learned nothing. That final scene was built to be the last scene ever of Curb, until it’s not. So we’re just going to have to wait and see. I thought Larry ran very well, for the record — Larry is very fleet of foot."

A hopeful discussion abounds below with Schaffer, as he provides insight into the Curb process and why he and creator David won't be making an official decision about the fate of TV Larry until they are good and ready. "I promise if we do do it again, there won’t be as long of a wait," Schaffer says. He also unpacks the potentially game-changing finale, revealing how they pulled off Fatwa! The Musical and what they would have done if Miranda wasn't available to play the part.

The final moment ends with Larry on the run from a threat on his life. Did you ever discuss an alternate ending?

From the moment we had the concept of the Fatwa! musical, we knew we wanted to end with the actual numbers of the production, and we knew we wanted to end with the duel. We always knew that’s where we were headed and that the duel was going to end the life of Fatwa! The Musical because of poor Lin’s throat. But that very last scene was not something we thought about until we drilled down on that final show. We realized that we needed to explain what had happened after the duel and wedding fiasco, and we were going to need one more surprise. Of course, the fatwa’s not over. That’s how we started; that’s how we should end.

The season began and ended with Larry skipping to a Mary Poppins tune. A lot happened in between, and yet he’s right back to where he started. What is the message you're sending?

I don’t think anyone has ever asked us what the message of our show is. (Laughs) When we write the show, we never put any thought into, “What’s the message?” We just try to make the funniest show possible. What was exciting about this season was that Larry has always had an antagonistic relationship with his environment, and this year we wanted to explore what would happen when it wasn’t just antagonistic, but that his world wanted him dead.

Now that he's actually being threatened, will this change Larry at all? Will he realize there are consequences to his actions — or, nah?

(Laughs) If you think that a life-or-death moment is going to make Larry appreciate that there are consequences to his actions, you do not know Larry. He’s one solid unit of Larry David. Indivisible, under angst.

How does Larry's obsession with the apology really bring the fatwa storyline full circle?

Larry fights for what is right. It may not be a big fight, but he’s always seeking justice. All he wanted was a "thank you" that was commensurate with the gesture. It’s not so much to ask. That’s one of the things I really enjoyed about this episode: that a tiny little thing like a muted "thank you" sets off an entire sequence of events that ruins his dream of Fatwa! The Musical. I also thought Larry and Lin’s dynamic was so perfect, Lin playing this peevish version of himself and just killing Larry with a smile until finally they both have enough of each other and it all blows up at paintball.

When did you come up with the idea to recreate the Hamilton duel, paintball-style, between Larry and Lin-Manuel Miranda?

When we were thinking about what to do with the season, it was a multi-step process. We knew we wanted to explain what Larry had been doing for the last five years. Then, when we knew he was going to have spent those years doing Fatwa! The Musical, we wanted to see a little bit of that musical. At that point we asked, “Well, who is going to play Salman Rushdie?” We loved the idea of Lin-Manuel Miranda, and once we figured that out, all roads led to a Hamilton-style duel, because Larry David is the Aaron Burr of our generation.

You said you wrote this musical subplot before even checking if Miranda was available. What would you have done if he couldn't do it?

We wrote everything without ever contacting Lin, which is a real nice parfait of hubris, naivete and stupidity. I guess we just kept thinking that he would want to do it and that he was available. The plan B was, I think, to just do eight episodes. (Laughs) I don’t know what we would have done.

The musical numbers were an entertaining feat. Who wrote the songs "I Do Not Like This Man" and "Salman Get Out," and what input did Miranda give?

The musical numbers were written by Larry, myself and [Oscar-winning composer for La La Land and Grammy winner] Justin Hurwitz. We wrote the lyrics and Justin did the music. Like most comedy shows, we try to have an Oscar-winning composer on staff, so that worked out! We would spitball lyrics in an embarrassing fashion and Justin would bring in his keyboard. We also wrote a few other songs that never made it in; we wrote a “Fatwa Sex” number, which I loved, but we didn’t have the time to shoot with Lin. We sent them to Lin saying, “Here’s what we did, if you want to change it, do whatever you want.” He actually was very happy with “Salman Get Out,” and he had one great note about “I Do Not Like This Man” — and he was 100 percent right, that it was sounding a little too Hamilton-esque. He thought it would be funnier if it was a little more dramatic, so we re-did the music — well, Justin re-did the music — to make it into the more dramatic version that you saw. There was just something so funny about seeing F. Murray Abraham as the Ayatollah. We also knew there was something about the gravitas of his presence that would be hilarious talking about Larry wearing the same pants. (Watch an exclusive deleted scene from that plotline above.)

How did you pull off the set productions and choreography for the musical numbers?

To class up the joint, we brought in [five-time Tony award winner] Susan Stroman, who handled all the choreography. She was amazing. We had an idea of what we thought those numbers were going to be, but she turned them into real, professional Broadway numbers. People were saying how difficult it must be to shoot those musical numbers, but it's actually completely different from Curb. They rehearse and do the same thing every time. When we’re shooting a Curb scene, I don’t know who is going to say what when. Here, it was like clockwork.

How long did you have to film those scenes, and how long were they able to rehearse?

We only had Lin for four days in June. We finished shooting everything at the end of March, and then we had to wait for Lin to come back from shooting Mary Poppins in London. We only had four days with him to shoot everything we needed for the finale — the duel, the ambulance and everything at the theater. His first day there was a little rehearsal recording the songs. Susan did an amazing job getting the cast ready. We’d rehearse one day and shoot the next. Each number took a half-day.

When you were creating this season, were you inspired by the fourth season of Curb, which also saw its plot surrounding a musical, The Producers, through to the end?

As we worked on this we were aware, obviously, that the Producers season had happened. The big difference here is that Larry is the writer and not performing. And we really wanted to show Larry getting everything he ever wanted — which is this musical he’s been working on for five years that now has the most talented singer-songwriter-performer on the planet in it — and it still doesn’t work out because of a "thank you," some weird cousins and outfit tracking.

How many times did you shoot the paintball scene, including the paint oozing out of Miranda's mouth?

We always knew we were going to intercut the paces of the duel with Jeff [Greene, played by Jeff Garlin] walking Sammi Greene [Ashly Holloway] down the aisle. The tricky part was how we were going to get Larry’s pants to fall down at the exact right time. We experimented with Larry walking in a lot of different-size pants so we could get a natural fall. With the paintball, we stuck that non-toxic blue paint in Lin’s mouth I think three times. (Laughs) He doesn’t need his throat, it’s not important! Usually, I will do anything that the actors are going to have to do to show them it’s not so bad, but that blue syrup he had to put in his mouth was very unpleasant. And the trickiest thing is how hard it is to pronounce "Burr" when you’ve got a pint of blue syrup in your mouth.

If you do come back, would you pick up with the fatwa right where it left off? Or not, given the open-endedness of it?

What this means for next season, if there is a next season — I’ll just say that we’re talking about talking about it. That’s the phase we are in right now. But I promise if we do do it again, there won’t be as long of a wait. When we’re thinking about ending a season, it's not just in the back of your mind but also in the front of your mind that “This may be it.” If Curb never existed again, is this an OK way to go out? And Larry getting chased by an angry Iranian who wants to kill him seems like as good of a way to go as any. One thing that I thought was going to happen at the end of this season that didn’t happen is that Larry did not get an actual fatwa. Real Larry David getting a real fatwa for playing fake Larry David who got a fake fatwa for doing a musical about Salman Rushdie getting a real fatwa didn’t happen. The real fatwa has remained elusive, but I’m very hopeful.

So if this were to be the end, do you both feel satisfied today?

If that were the last Curb, I would be pretty satisfied. I thought the season finale was a great way to wrap up all the different story threads we’d been exploring all year. But I will say this to anyone who is now going, “Oh no, it’s never coming back” — the only way there can be another season is if Larry feels creatively that he has ideas for it. I’m willing to bet that he’s going to get himself into some more awkward situations.

Has he been carrying around his little notebook and jotting down material? And do you do the same?

Larry is always carrying around his notebook. Now that we’re not shooting and everyone is out in the world, I’m sure he’s filling that notebook. I used to carry a notepad, and now I just jot notes down in my phone. Sometimes I’m talking to people and they think I’m writing an email and really I’m writing about what terrible or annoying thing they just did. It’s a pretty extensive file. People aren’t great, in general. (Laughs) Some are hopeful that what they did is going to be on and will say, “Oh, this better not show up on Curb!” But those are never the ideas that end up on the show.

You’ve spoken about your Curb process: you and Larry come up with the ideas and outline the show, and then you give HBO the go-ahead. How far along in that process are you for season 10?

We really are at the stage of talking about talking about it — and that’s how every season starts. Larry never wants to commit to a season unless he’s absolutely sure he’s going to like everything that season entails. He never wants to feel like he has to do the show because he said he’d do the show. So if we do another season, we’ll work on it until he’s super happy with it and confident that he’s actually going to shoot the episodes, and then we’ll tell somebody so we can actually shoot them.

Is part of the luxury of working with HBO at this point that you are able to have such a flexible timeframe?

Every season is sort of like cooking: It’s ready when it’s ready. It’s hard to say when we’re going to have something to share with everybody if we do it. HBO has been amazing about letting Larry follow his own process. If it takes six years, it takes six years. I think the wait was worth it.

When you look back at this season — with its many supersize episodes, massive guest-star roster and mini-musical production — does this one feel like a bigger accomplishment?

The simple fact that we actually finished a season is an accomplishment. Every script that we write on the dry-erase board has a point where we get stuck. Larry stops at that spot and says, “This one is harder than all the others.” He has said that for every script. So the fact that these shows exist at all is a minor accomplishment. Then the fact that we got Lin to actually come and play with us for a week was a major accomplishment. We needed him to make the shows work, but he came and made them amazing. Saying that he’s talented is like saying kittens are cute or the Winter Olympics are stupid, it’s obvious. But he just really came to play, and his dynamic with Larry was fantastic.

You had said this finale was the most "ambitious" episode you ever did, and that it worked. What were you referring to, specifically?

This season finale was probably the most ambitious thing we’ve ever done because we wrote it for somebody who didn’t know that we had written it for him, who happened to be in London, and we needed to actually write parts of a musical. From a scheduling and production standpoint, it was ambitious. Larry and I are not musical theater people; that was ambitious. Aside from all of those logistics, we wanted it to be really funny. Also, guest cast-wise it was ambitious, with F. Murray Abraham, Nick Offerman, Casey Wilson and Lin. Everyone just delivered.

Do you or Larry read reviews when the season is over, and do you take critics into account when thinking about the next season?

I don’t really read reviews, and I’m sure Larry doesn’t. We’ve never spoken about them, so I’m guessing he doesn’t read them. Reviews for us are usually people whose taste we trust saying, “Oh, that was funny.” We want the audience to laugh, and we want the audience to like it. If some people don’t, that’s OK. We’re pretty hard to please, so if we like it that’s enough for us.

One thing that wasn’t resolved was Larry and Cheryl [Cheryl Hines]. Why did you leave Cheryl and Ted Danson's relationship going strong — is she simply too good for Larry at this point?

We actually had some other ideas that we wanted to do with the Ted-Cheryl-Larry relationship, but there just wasn't room to fit them in this season. If we ever do another season, there are definitely ideas we’ve been entertaining for Cheryl and Ted and what that means for Larry.

What else is left? And is that typically how Curb works, where you end up with a batch of stories to mine from?

Almost every episode this season had an idea that we had to pull out of it because it was too full. There are ideas lying around; sometimes they find a home and sometimes they don’t. It’s an evergreen business chronicling the lives of selfish people — this town gives you a lot of inspiration. This is from Seinfeld, but I always used to say that you walk around with a bag of apples and take one out and say, “Is this going to work? No.” And then you shove it back in the bag. We all have these long lists of stories we’ve never done. This season's "disturbance in the kitchen" storyline is a perfect example. That one sat there for two seasons with us not knowing what to do with it until this year.

When you first talked about coming back, did you say: "If we're going to do it, let’s make more than one season"?

When we were talking about coming back, it was not, “Let’s come back and keep doing it.” For Larry it was, “Will anyone want to see this? Will anyone want to do it?” He was not thinking about a larger plan; he was wondering if anyone would even want to watch if we came back. When Lin said yes, there was a tremendous sense of relief. But still, we knew we needed him; we didn’t know just how great he and Larry would be together. One thing Larry is very happy about is that none of the big plot points got out. Lin, Larry and I all really wanted it to be a surprise for the audience, and somehow, even through all the scenes in the agency last week and shooting these musical numbers, it stayed secret. He’s very happy about that.

This season answered what Larry had been up to all these years. How does that bring a different kind of pressure when plotting what could come next?

Every time you finish a season there is relief that you finished a season and then there is the pressure of, “How could we ever do this again?” I never thought we could top the Seinfeld reunion season of Curb, but then we went to New York and everybody had a great time. If you think about it that way, you’ll never get out of bed. You have to just keep putting funny stories together that make you laugh. For there to be funny stories, Larry has to get into strange predicaments and awkward situations in real life, and I’m willing to bet that he does.

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