In the small town of Derry, Maine, children begin to disappear at an alarming rate. Among the terrorized townfolk is a group of seven misfit kids known as the Losers' Club, each with their own personal fears and encounters with the predatory force. The group's leader, Bill Denbrough, is particularly affected; his younger brother, Georgie, fell victim to the malevolence lurking beneath the town's surface. The creature, which they come to know as "It," terrorizes them in various forms, exploiting their individual phobias. Realizing they're all haunted by the same sinister presence, the friends vow to stick together, suspecting that "It" has a cycle of hibernation and emerges every 27 years to prey on Derry’s children.

Determined to put an end to the horror, the Losers' Club bands together to confront and battle the entity. As they uncover more about "It," they learn that it primarily appears as Pennywise, a malevolent clown. Delving deeper, the kids discover that Pennywise’s influence is intricately woven into the history of Derry itself, dating back centuries. The group's unity is tested as they face their individual fears in order to overcome the shapeshifting menace. As they get closer to confronting Pennywise, they must come to terms with the reality of growing up in a world where the horrors of childhood can be all too real and sometimes come in the guise of what one fears the most.