In the Mouth of Madness (1995)

John Trent is a cynical insurance investigator. When bestselling horror author Sutter Cane disappears, Trent is hired to try to track him down. Trent experiences terrible nightmares after reading a few of Cane's novels and learns that people have allegedly been driven mad by them. Trent and Linda Styles, Cane's editor, set out to look for him and find themselves in a town with the same name as the town in Cane's fiction. The town's landmarks are also the same. As Trent digs deeper into the fate of Cane, he begins to call the nature of reality itself into question.

In the Mouth of Madness is a horror movie featuring Sam Neill.

It is possible to buy In the Mouth of Madness on Amazon Video, Apple TV, DIRECTV, Google Play Movies, Microsoft Store, Vudu and YouTube.