Mandy Gladstone is struggling to write a play about her father Clark, an inventor. She relives her adolescent fascination with Clark’s secretive nature, his manic episodes, his trips to California, and how, at the end of his life, he received a series of mysterious and threatening postcards from Sadie Hurtz, a giant doll shackled to a chair in an abandoned amusement park trailer. When Mandy herself receives similarly threatening postcards from Sadie, she decides to investigate. Her pursuit of the truth reveals carefully guarded secrets about her family, about her father, and about the haunted nature of creativity.