It's Halloween season in Thornapple Springs, Michigan, and Didi couldn't be more excited! This is her favorite time of year to think up new ways to scare her older brother, Pete. Though Pete has won the "scaring game" year after year, Didi thinks this time victory will be hers. Thornapple Springs is also home to Mrs. McNaughtlebean, who is hardly ever seen by the townspeople. The elderly women lives in the scariest looking house in town. For years, many of the younger locals have referred to her as "The Witch." Didi comes up with a brilliant plan to dare her brother to go trick-or-treating and ring the front doorbell of the witch's house. The challenge will be to convince both Pete and her best friend, June, to do so. Before Halloween night, Didi decides to check out the dark, mysterious house for herself on her way home from school. While there, she has a strange and frightening encounter.