Time will tell if the remake of Stephen King’s IT will scare a new generation of horror fans. But already, its menacing star, the “clown” Pennywise, has successfully spooked one group: the movie’s cast.

Director Andrés Muschietti brought a few clips of IT to SXSW 2017, as well as a few tidbits about what to expect. Early press images of Pennywise have already done the legwork of visually separating Bill Skarsgard’s version of the character from that of Tim Curry’s portrayal. But according to Muschietti, the two Pennywises also have different personalities.

Curry’s clown was a cartoonish nightmare in need of dental hygiene. In one of the film’s most iconic scenes, a little boy named Georgie loses his paper boat in the sewer. When he peers into the darkness below, he’s confronted by Curry’s chatty clown, who announces his presence with a saccharine “Hi, Georgie!” Muschietti teased his take on the scene with a short clip, and the difference is immediate. Skarsgard’s Pennywise has a far more sinister edge, marked by piercing yellow eyes and contorted movements. For those who are familiar with the source material, the anticipation of what’s to come makes the entire sequence agonizingly tense.

The director remains insistent on keeping Pennywise’s secrets. He’s been tight-lipped about the character, even with his cast. When preparing for the film, he did his best to keep Skarsgard separated from the film’s child actors. The actor wasn’t introduced to the young cast until Pennywise’s first encounter with the children. “It was something that we agreed on, and that's how it happened,” he said.

The tactic proved to be an effective one. The young cast was confident they wouldn’t be afraid of their painted adversary. They were wrong. “The day that he showed up on the stage, they fucking freaked out,” Muschietti said. “Bill is like, seven-foot high, and I can't describe how scary he looks in person. He's a wiry man, crouching, making sounds, snotting, drooling, speaking in Swedish sometimes. Terrifying.”

Muschietti’s version of It will also take care to expand the story of the Loser’s Club, the group that connects the kids. The film will also add plot beats and scenes that don’t appear in either the novel or miniseries. It will, however, still use the town of Derry to help illustrate just how deep Pennywise’s influence runs. “[Derry is] not only the place where the Losers live and have their exchanges, but it's also the extension of the evil of Pennywise,” he said.

“The sense of dread that grows in Derry is part of the dread of Pennywise. Pennywise is not just a character that is shapeshifting. His influence is all around and he's projecting this in the town of Derry and in the grownups of Derry. It's all part of that atmosphere of dread that is even the anticipation than the scares in this movie.”

It hits theaters in September. When asked about rumors that an “It: Part 2” would begin filming this month, Muschietti brushed them aside. "It's just a complete misinterpretation of the facts,” he said. “It's not happening now. We're in the midst of post [production].”