故事发生在1884年的英国，伊诺拉（米莉·博比·布朗 Millie Bobby Brown 饰）正准备迎接自己的16岁生日，哪知道在这一天，她的母亲（海伦娜·伯翰·卡特 Helena Bonham Carter 饰）失踪了。大名鼎鼎的名侦探夏洛特福尔摩斯（亨利·卡维尔 Henry Cavill 饰）和麦考夫（山姆·克拉弗林 Sam Claflin 饰）成为了伊诺拉的监护人。　　面对古灵精怪不受控制的妹妹，两个男人一门心思的想要将她送到专门培养“淑女”的寄宿学校中就读，伊诺拉哪会这样乖乖受人摆布？一言不合之下，她选择了离家出走，只身一人前往伦敦寻找母亲的下落。在旅途中，伊诺拉被卷入了一个非常神秘的案件之中，她化身成为侦探，和自己的哥哥展开了斗智斗勇的较量。

Joanna moves with her young son, Alfie, to the quiet town of Flinstead, seeking a fresh start. However, she quickly becomes entangled in the lives of local mothers and the unsettling dynamics of the community. When Joanna stumbles upon an online rumour about a child killer living in the town, she uses it to win over the mums at the school gate. As gossip spreads, suspicions build, and Joanna finds herself drawn into a web of secrets and paranoia. Balancing her efforts to protect her son with the growing unease in town, Joanna struggles to distinguish between truth and hearsay. With relationships strained and emotions running high, the boundaries between trust and fear blur.                                                                    　　The Rumour explores how quickly small-town gossip can spiral out of control, forcing Joanna to confront the unforeseen consequences of curiosity and mistrust in her search for answers. The story is based on the Sunday Times bestselling book by Lesley Kara.