Cold-blooded Myrtle

Summary: "Twelve-year-old Young Lady of Quality and Victorian amateur detective Myrtle Hardcastle returns, and now she’s on the trail of a serial killer in her hometown of Swinburne.  When Mr. Leighton, proprietor of Leighton’s Mercantile, is found dead on the evening his annual Christmas shop display is to be unveiled, it’s clear a killer had revenge in mind. But who would want to kill the local dry-goods merchant? Perhaps someone who remembers the unresolved, long-ago scandal that occurred when he was a professor and archaeologist. When the killer strikes again, ­­­each time manipulating the figures in the display to foretell the crime, Myrtle finds herself racing to uncover the long-buried facts of a historical scandal—and the motivations of a modern murderer. " -- goodreads.com