Adelaide, 1931: Telephone switchboard operator Frances' life is difficult as sole provider for her mother and adopted uncle. But it's thrown into turmoil when she overhears a suspicious conversation on the phone, planning a murder. If a life is at risk, she should tell the police; but that would mean breaking her confidentiality clause and would cost her the job. And Frances soon begins to doubt the evidence of her own ears - it was a very bad line, after all... She decides to put it behind her, and meets slightly dangerous nightclub owner Jack. Jack's no angel - but when Frances' earlier fears resurface, she knows that he's the person to confide in. Frances and Jack's hunt for the truth puts them in grave danger, and soon enough Frances will learn that some things are a matter of love and death?