Walking her dog one night, Gemma Doyle of the Sherlock Holmes Bookshop acts quickly when she smells smoke outside the local museum. Many treasures are burned, so local shop owners come together to hold an afternoon auction tea to raise funds to rebuild. Before the gavel can fall, museum board chair Kathy Lamb is found dead. In this fourth case (after The Cat of the Baskervilles), Gemma's best friend Jayne is one of the many suspects, and Gemma risks displeasing her boyfriend in blue in an attempt to solve the mystery.