Charlotte, an alienated sound engineer, travels to the country home where her mother was just murdered. She is quickly frustrated by the lack of progress in the police investigation and so begins her own. While listening to a fresh sound recording she made in her mother's house, Charlotte discovers a strange phenomenon, she can hear sounds from the past in her headphones. Soon she is using this ability to hear the past to piece together the last few days of her mother's life, drawing ever closer to discovering who killed her, even as the murderer returns to try and eliminate Charlotte before they are discovered.