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.

A man who specializes in debunking paranormal occurrences checks into the fabled room 1408 in the Dolphin Hotel. Soon after settling in, he confronts genuine terror.

After a violent storm, a dense cloud of mist envelops a small Maine town, trapping artist David Drayton and his five-year-old son in a local grocery store with other people. They soon discover that the mist conceals deadly horrors that threaten their lives, and worse, their sanity.