Brian Truitt

USA TODAY

Seeing a red balloon isn’t a good thing in the horror movie It. That means Stephen King’s iconic killer clown Pennywise is back in town.

An updated adaptation of King’s 1986 best-selling novel, It (in theaters Sept. 8) turns Pennywise (played by Bill Skarsgård) loose on seemingly quaint Derry, Maine, where a group of kids known as the Losers’ Club attempts to stop him and his latest murderous mission. The movie is the first of a planned two-part epic directed by Andrés Muschietti (Mama) with a narrative like the book that spans two time periods, following the main characters as children in 1989 (in the book, the story starts in the 1950s) and as adults three decades later.

Derry has an infamous history of missing youngsters, and the culprit is an evil nameless entity that appears every 30 years and lurks in the underground sewer system. When young Bill Denbrough (Jaeden Lieberher) loses his brother to Pennywise’s latest reign of terror, he teams with a bunch of other children who’ve also encountered the malevolent force: overweight Ben Hanscom (Jeremy Ray Taylor), loudmouth Richie Tozier (Finn Wolfhard), clean freak Stan Uris (Wyatt Oleff), history lover Mike Hanlon (Chosen Jacobs), hypochondriac Eddie Kaspbrak (Jack Dylan Grazer) and tomboy Beverly Marsh (Sophia Lillis).

With these local misfits having to step up against pure evil, one of the major themes explored is innocence lost. “It happens in the book, this coming of age and kids facing their own mortality, which is something that in real life happens in a more progressive way and slowed down,” Muschietti says. “There’s a passage (in It) that reads, ‘Being a kid is learning how to live and being an adult is learning how to die.’ There’s a bit of a metaphor of that and it just happens in a very brutal way, of course.”

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Another small part of King’s 1,138-page tome gave rise to the director's vision for Pennywise, in which Bill wonders if this monster is eating children because that’s what we’re told monsters do.

“It’s a tiny bit of information, but that sticks with you so much,” Muschietti says. “Maybe it is real as long as children believe in it. And in a way, Pennywise’s character is motivated by survival. In order to be alive in the imagination of children, he has to keep killing.”

Tim Curry’s Pennywise scared a generation of audiences in TV's 1990 It miniseries, yet Muschietti promises Skarsgård’s version is more terrifying because of the clown's wholly capricious nature.

“It’s established that Pennywise takes the shape of your worst fear,” Muschietti says. “He doesn’t have a steady behavior, he doesn’t expose how he thinks, and that’s what makes him really unpredictable.”

And because no knows what he’ll do next or how, the space between appearances — with the occasional red balloon creepily floating by — becomes a “feeling of dread that grows in people’s minds.”

This movie focuses on the kids and the next film will feature their grown-up selves coming to grips with the past as their old enemy resurfaces.

“It’s about remembering things that they have forgot. Getting back in touch with those memories is such an important part of the plot,” says Muschietti, adding that there are a few hints in this fall’s It “that make you think about what will happen 30 years later when Pennywise comes again.”