When Molly moves into her new apartment after a tragic accident, a strange noise from upstairs begins to unnerve her. The disturbing knocking sounds like a call for help or perhaps a message in morse code. As its intensity grows, she confronts her neighbours, but it becomes clear that no one can hear what she is hearing. As everyone starts to question Molly, including Molly herself, she is thrust into an unsettling quest to uncover the truth in a world where truth and reality appear to be just beyond her reach.