When Dr Huxtable (no, not that one) makes a desperate appeal to Sherlock for help in locating a missing pupil of his stuffy boarding school, Holmes politely declines. When he learns of the £6000 reward, however, and of the blue bloods behind the intrigue, the great detective does an about turn and catches the next train north! A case of murderous intrigue, ransom and bike-tire forensics quickly thickens around our hero. Scott's choice for "Sherlock Selects" comes from a December 2017 chat and closes out the retrospective Summer series for another year.