What source material is Knock at the Cabin based on?

Knock at the Cabin is based on the play "The Open Window" by Susan Hill. The play was first performed in 1989 and tells the story of a woman who, while staying in a remote cabin, is subjected to a mysterious knocking at the door. The play is a psychological thriller that explores the themes of fear, guilt, and the unknown. It tells the story of a woman who is haunted by the memory of a traumatic event that happened in her past and how she deals with the fear and confusion of the unknown.

The original play has been adapted into the film, Knock at the Cabin. The film follows the same story and themes as the play but with a few changes. The main focus of the film is on the character of the woman and her struggle with her fear and guilt. The film also adds more suspense and tension, as well as exploring the theme of paranoia and the fear of the unknown even further.

Overall, Knock at the Cabin is based on the play "The Open Window" by Susan Hill. The film follows the same story and themes as the play but with a few changes, adding more suspense and tension. It explores the themes of fear, guilt, and the unknown, as well as paranoia and the fear of the unknown.