Gemma Doyle is dragged into a mystery when 10-year-old Lauren Tierney comes to the Sherlock Holmes Bookshop and Emporium wanting to hire a consulting detective. Lauren's mother has been accused of the murder of her gardening club rival, who she was seen arguing with earlier in the afternoon, before the woman's body was found. Despite herself, and despite the disapproval of her police detective boyfriend Ryan Ashburton, the game is once again afoot, and Gemma finds herself and Jayne Wilson using their powers of deduction to ponder yet another curious incident.