Charlotte is a sound engineer who 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 decides to begin her own investigation. While listening to fresh sound recordings she has made in the 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. She draws ever closer to discovering who killed her, even as the murderer returns to try and eliminate Charlotte.