December 19
From mrspencil: a bookstore is the scene of a crime
"I can't understand how such an item went missing?" the bookseller adjusted his spectacles and peered at the narrow section on the shelf, which no long contained the volume. "There were no footprints, no broken glass, no marks on the lock. I did not notice anyone suspicious looking around last evening either."
Holmes and Watson began to examine the store for clues to the thief.
"Nothing, Watson," the detective turned a frustrated stare upon the undisturbed polished lock of the front door. "No sign of a forced entry. No prints. Not a scrap of clothing."
"There were those broken walnut shells in the corner," Watson shrugged his shoulders.
Holmes brought out his magnifying glass and examined the pile of husks. He popped a small item into a collection vial. "You are invaluable, Watson." He held up the vial for the doctor's closer inspection.
"Ah, I see. Shall we return home?" Watson asked.
~o~
Later that day, Basel and Dawson carefully listened to Holmes' narration of the facts. A missing book with only some gnawed walnut pieces left behind and a single strand of mouse hair.
"I believe I may be able to help you," Basel squeaked. "There has been a string of murders amount the rodentia, specifically the muridae family. Based on the symptoms, I am suspicious that someone is using arsenic to poison the victims. I shall send my associates out tonight to investigate the alleyways. I am sure this book is related."
Dawson's whiskers quivered. "I'm sure those who have borrowed the book will return it once they are finished."
Watson broke off a bit of Mrs Hudson's shortcake and handed pieces to both mice. "Thank you for your assistance in this case. Together we can remedy this bookstore crime."
A/N: The book in question was published in 1818 by Mathieu Orfila: Secours à donner aux personnes empoisonnées et asphiyxiées (A popular treatise on the remedies to be employed in cases of poisoning and apparent death)