Gemma Doyle is walking her dog when she smells smoke outside the West London Museum. No one is hurt, but the museum's priceless collection of furniture can't be saved, and damage to the historic house is extensive. Baker Street's shop owners hold an afternoon auction tea to raise funds to rebuild, and Great Uncle Arthur Doyle offers a signed first edition of The Valley of Fear to auction. Before the gavel can fall, museum board chair Kathy Lamb is found dead in the back room. Wrapped tightly around her neck is a long rope of decorative knotted tea cups-- a gift item that Jayne sells at Mrs. Hudson's Tea Shop. Fellow shopkeeper Maureen becomes the prime suspect, and begs Gemma for help.