Welcome to It’s a Hit! In this series, IndieWire speaks to creators and showrunners behind a few of our favorite television programs about the moment they realized their show was breaking big.

[Editor’s note: The following interview contains spoilers for “It: Welcome to Derry.”]

Children who have never seen “It” still love Pennywise. It’s one of the weirder cultural phenomenons surrounding Stephen King’s legacy in horror today. Long before these teeny-tiny cinephiles are old enough to read about literature’s most notorious killer clown — let alone watch Bill Skarsgård terrorize an entire damn town across time and space on screen — they draw Pennywise. They dress like Pennywise. They have themed birthday parties and even sleepovers honoring… Pennywise.

“It’s irresistible for young kids,” said Andy Muschietti, co-creator and director of “It: Welcome to Derry!,” laughing with IndieWire. “I can’t explain it, honestly.”

Neither Andy nor his sister and producing partner Barbara Muschietti (also the series co-creator, with longtime collaborator Jason Fuchs and Brad Caleb Kane as co-showrunners) seemed interested in over-analyzing the bizarre trend, either. Already deep into preparations for “It: Welcome to Derry!” Season 2, the siblings didn’t talk about the intergenerational appeal of Pennywise like franchise architects focused on optimization. Instead, they acted more like mischievously proud babysitters — amused but still too busy chasing the rush of witnessing something dangerous or unexplainable themselves.

“Maybe there’s some sort of aesthetic attraction to Bill’s face,” Barbara theorized. “It’s that angelic Pennywise face. Those big blue eyes. There’s something child-like about him.” 

Raised in Argentina less than two years apart, Andy and Barbara Muschietti grew up glued to late night broadcasts and double features at their local movie theater. Those early experiences with horror cinema shaped the modern caretakers of King’s widely beloved “It” universe, and silently linked the renowned American author and his home in Maine with two of his most acclaimed successors, thousands of miles away and years before they met.

The brother and sister recall reading King as teens, but even younger than that, they were drawn to the infinite possibilities of stories inspired by the things that scare us. 

“There was a high that came with watching those movies, a feeling that we could actually do this work,” Barbara said. “That was very empowering for little us.”

That same sense of alien fascination now fuels Andy and Barbara’s smash-hit TV show for HBO, expanding on the King mythology the Muschietti siblings already adapted across two smash-hit feature films for Warner Bros. Starring Taylour Paige, Jovan Adepo, Chris Chalk, James Remar, Madeleine Stowe, Rudy Mancuso, returning Bill Skarsgård as Pennywise, and more, “It: Welcome to Derry” follows a new generation of residents as the town’s most notorious tormentor resurfaces. Although Season 1 is set in 1962 — 27 years before the cyclical awakening of Pennywise in the Muschiettis’ first movie — the brilliant finale episode (one of four directed by Andy) revealed that the spin-off series isn’t really a prequel at all.

“It’s an extrapolation,” Andy said, explaining how he, Barbara, and the rest of the “It: Welcome to Derry” team expand on the supernatural and philosophical architecture in King’s undeniably dense text from 1986. Framed in part around the grandparents of iconic Losers’ Club member Mike Hanlon, and his obsessive research into Derry’s violent past, the edgy and imaginative series revisits multiple incidents from the town’s history. Simultaneously, the setting itself becomes a kind of haunting character, as a living ecosystem of repression and collective denial help propel Pennywise toward his depraved goal. 

“This is an attempt to basically explore those enigmas and build stories around them,” said Andy. 

“We’re incredibly lucky because Stephen is so generous allowing us to do this,” Barbara continued. “He reads everything before it’s put into motion and he’s been so supportive.”

Describing King’s feedback as having a kind of “childlike enthusiasm,” the eldest Muschietti said the siblings’ collaborative relationship with the author has evolved significantly since their first film. Of course, that trust was hard-earned. Released in 2017, “It” became the highest-grossing horror movie in domestic box office history at the time, eventually earning more than $700 million worldwide and helping transform the Muschiettis from promising genre talents into major Hollywood players. 

In 2019, follow-up “It: Chapter Two” grossed another $470 million globally, proving audiences weren’t simply nostalgic for Pennywise, but fully invested in the Muschiettis’ expanding artistic perspective on King’s popular fictional world. With that major industry success behind them, “It: Welcome to Derry” wasn’t so much an attempt to recreate what worked before as it was an opportunity for Andy, Barbara, and even King himself to roam around inside the cursed place they only thought they knew well.

“You can tell that it’s fun for him to go back to this world,” Andy said. “It’s about creation now.”

The filmmaker described early communication with King as relatively minimal. Now, the siblings regularly discuss entirely new storylines and creative expansions with the author directly. That primarily involves narrative ideas that venture far beyond King’s original novel, and in some cases, fundamentally reframe the facts of the book from 1986. Re-positioning Pennywise not just as an ancient monster haunting a small town on a 27-year schedule, but as a being capable of moving through time in an effort to alter the events surrounding his eventual death is bold. 

“But it’s a lot more unplanned than it looks,” Barbara joked.

For most King fans, that kind of free-wheeling lore expansion would become overwhelming. But the Muschiettis’ warm sibling dynamic keeps the material mostly grounded. Even when Andy starts spiraling into discussions about cosmic turtles, destiny, and temporal manipulation, his big sister anchors that playful back-and-forth in serious creative rigor. Barbara called “It: Welcome to Derry” the hardest project of her career, even after nine feature films.

“We went in a little naively thinking TV’s going to be easier,” she admitted. “It’s definitely harder.”

“I just went on marathon mode,” Andy said. “There’s something natural in us, which is preserving the film quality, I think. Whatever we’re doing is working.”

Part of the series’ core challenge came from the Muschiettis refusing to scale down their cinematic ambitions. “It: Welcome to Derry” was conceived with high production values in mind, and the team was dedicated to delivering on that vision — even while navigating industry strikes (which delayed production on the show for nearly nine months in 2023), and the logistical demands of making an eight-hour season feel cohesive. 

“The dream is still the same size,” Barbara said. “We don’t know how to reduce our dreams.”

That maximalist energy extends beyond jump-scares and into the series’ all-too-resonant theme. While King’s “It” has always explored trauma, grief, and cyclical cruelty, the Muschiettis are pointedly interested in the political dimensions of fear itself. That’s something Andy discussed with unusual directness under the existential cloud of the current U.S. administration. 

“We live in a time where fearmongering is practiced a lot,” he said. “People should know that it’s a construction — not everything that comes from ‘up there’ is true. It’s orchestrated to divide us and make us fear each other for profit.”

Per the director, “It: Welcome to Derry” Season 1 centers on “the weaponization of fear,” but future installments will tackle “the weaponization of faith” and “the weaponization of love.” That’s still intense emotional and intellectual material for a mainstream TV series, but the Muschiettis, much like King, refuse to frame their work as an abstract allegory. Andy and Barbara attribute the allure horror media to survival, manipulation, and the unavoidable pull of collective psychology — concepts that were embedded into every page of “It” nearly 40 years ago.

“The fog is something that runs across all three seasons,” Andy explained, referencing King’s recurring motif of denial. “People, out of fear, decide not to look into things or to just turn away.”

“We are living in a world where the weaponization of fear is something that has to be fought daily,” Barbara said. “If we are not aware, and if we don’t fight it, we will succumb like Derry.”

For all the heavy sociopolitical lifting happening inside “It: Welcome to Derry,” the Muschiettis remain deeply joyful storytellers. Much of the siblings’ conversation with IndieWire drifted back to the strange wonder of children becoming obsessed with Pennywise, and that behavior became easier to understand when Andy shared his own tale of forbidden iconography. He compared the experience of kids loving Pennywise to his younger self becoming inexplicably obsessed with the band Kiss, long before understanding the music itself.

“Something about the aesthetics,” he recalled. “Something mysterious and scary and dark.”

That attraction clearly still fascinates him and his sister. So does the possibility that stylishly rendered nightmares can push audiences toward something larger than passive entertainment. By the end of the interview, both Andy and Barbara transitioned from discussing their show amid Emmys season, to passionately encouraging their viewers to read, write, and think critically.

“We need young people to be writing cries against fascism like ‘The Long Walk,’” Andy said, noting that King wrote his first novel as a teen. (It was published under a pseudonym in 1979). 

“I hope young people get to read Stephen King and have the experiences we had reading King,” Barbara said. “For that, you have to make time away from screens. So, please watch the show, but then go read and go write.”

“It: Welcome to Derry” Season 1 is now streaming on HBO Max.