Visiting her sister in Bogota, Jessica (Tilda Swinton) is awoken by a loud bang, audible only to her. Restless and disoriented, she roams the city in search of an explanation for the mysterious sound, becoming immersed in the aural richness around her - whispers in a hospital room, sound effects playing in an editing studio, indiscreet noises from a city square. Despite being present throughout, Jessica's motives remain opaque and her encounters enigmatic. Soon she begins to confront the unsettling sights and sounds that call her identity into question.