There's been a murder at the racing stables and Gertie's father, Patrick, stands accused. The punishment is death by hanging, and Gertie is beside herself. She knows her father didn't do it, but with Sherlock Holmes away, how can she prove his innocence? Wiggins suspects an inside job and sends Sparrow in to do some digging around. Undercover as the new stable lad, Sparrow finds himself mixing with some decidedly shady characters - and then he stumbles upon an audacious betting scam that puts a valuable racehorse in danger. Now there are two lives for the Baker Street Boys to save, and time is not on their side. The race is on!.