"The Telephone" is a fictional spy story set primarily in rural Queensland, Australia, spanning several decades. The narrative follows Matilda (Maddy) and her husband Bernard as they uncover secrets surrounding their property, including connections to Nazi war criminals and hidden diamonds. The story focuses on Matilda's life from 1954 to 2025, including marriage and a tragic death which changes her life. Alois Pfeiffer, a German Jeweller and former spy, aids them in the process. After Bernard's death, Matilda grapples with loss, but later finds a renewed purpose as she investigates the truth behind her husband's death. Later in her life, she is aided by her sister, Kathleen, in uncovering more secrets related to the house, in a quest for long-hidden diamonds.