Following the time leading up to the events of the first film in the Stephen King 'It' series. A group of misfits vow to find their missing classmate. At Derry Air Force Base, Major Leroy Hanlon arrives to a mixed reception.

Charlotte and Will navigate their new life at the town of Derry; Ronnie worries about her father's fate.

General Shaw pushes ahead with his mission, ordering Leroy and Pauly to escort Dick Hallorann on an aerial search for a new dig site. Rose attends a tribal meeting. Ronnie, Lilly, Will, and Rich attempt to get visual proof by conjuring an Orixá.

Children encounter frightening situations while Charlotte supports Hank and General Shaw increases pressure.

While the tribal Keepers strategize how to contain increased aggression in town, the military descends on Neibolt Street, and the kids head into the sewers with their own objective.