Evi lives with a sick mother who is in a coma, and hosts a podcast about paranormal phenomena with her friend Justin. One day the hosts receive frightening audio recordings from a certain married couple: the wife sings children's songs in her sleep, but on the reverse playback of the recordings Evi notices sinister messages addressed to her. The recordings seem increasingly terrifying to Evi, and gradually unexplained and disturbing phenomena begin to occur around her.