When young television producer, Fliss Benson, is suddenly put in charge of a ground-breaking documentary about miscarriages of justice involving a string of cot deaths, alarm bells ring.
Her boss, a man whose "weirdness" quotient she monitors on a daily basis from her office window, has long championed this high-profile project. It seems unlikely that he would relinquish it to a nonentity such as herself. So when it emerges that one of the mothers involved in the film has been found murdered, Fliss's suspicions about chalices and poison are confirmed.
Although the novel can feel overwhelmed by off-piste police procedural, Sophie Hannah fans will welcome the return of investigator Snowman Proust and sidekicks Simon and Charlie.