'Knocking' Review: Stylish Swedish Gaslighting Thriller Keeps Its Protagonist on Edge, But Not the Audience 'Knocking' Review: Stylish Swedish Gaslighting Thriller Keeps Its Protagonist on Edge, But Not the Audience Following an anxious woman's terror that an unseen neighbour might be in peril, Frida Kempff's well-made debut feature knows its genre traditions, but not how to rework them. Guy Lodge, provided by FacebookTwitterEmail Running time: 1 hour 18 minutes Courtesy of Lask Film The word “gaslighting” is so broadly used these days — its definition, in some quarters, having evolved into a synonym for “lying” — it’s almost reassuring to see a psychological thriller that cleaves to its original sense. No one else gets much reassurance, however, in “Knocking”: a Swedish creeper that, as in “Gaslight” nearly 80 years ago, sees a frail female protagonist’s mental health history weaponized against her, making her question her grip on a possibly sinister reality.