Adelaide Hills, Christmas Eve, 1959. At the end of a scorching hot day, beside a creek in the grounds of a grand and mysterious house, a local deliveryman makes a terrible discovery. A police investigation is called, and the small town of Tambilla becomes embroiled in one of the most shocking and perplexing murder cases in the history of South Australia. Many years later and thousands of miles away, Jess is a journalist in search of a story. Having lived and worked in London for nearly two decades, she now finds herself laid off from her full-time job and struggling to make ends meet. Until a phone call out of nowhere summons her back to Sydney, where her beloved grandmother, Nora, has suffered a fall and been raced to the hospital. At Nora's house, Jess discovers a true-crime book that chronicles the police investigation into a long-buried event: the Turner Family Tragedy of Christmas Eve, 1959. It is only when Jess skims through the pages that she finds a shocking connection between her own family and this once-infamous scandal - a murder mystery that has never been resolved satisfactorily.