In the quiet town of Derry, Maine, seven freinds, Bill, Eddie, Mike, Bev, Stan, Richie and Ben (The Losers Club) have all been seeing and hearing strange things. Most of which revolve around a Clown called Pennywise, which they all admit being real. The kids eventually discover that the leader of the club, Bill’s little brother, fell victim to this evil. The group sets out to stop the force and put it to rest once and for all. 30 years after defeating IT, Mike Hanlon, the only Member who remained in Derry, suspects that IT has returned and is forced to call back all of the Losers club, due to a promise they all made to return if its evil shall ever resurface. Uncovering new powers, clues and evil the club reunites as adults and come face to face with the evil that has haunted and fed on Derry for the last centuries.
A series of murders prompts Mike Hanlon to suspect that the supernatural menace that he and a group of friends battled as children has returned. He begins to call his friends to remind them of the oath they swore: if It returned again, they would come back to Derry to do battle again.