221b Baker Street has never lacked for visitors.
Princes and kings, washerwomen and governesses, the lost and the liars. But never one such as this.
But in the final days of the Boer War, Sherlock Holmes receives a most unexpected guest. A serving girl, whose clothes are ten years out of date and speaks in repeated phrases. She answers any question put to her with mathematical exactitude. More shocking is the secret hidden under her bonnet…
As Sherlock Holmes contends with this case, he must confront a master thief, a supposed ghost, uncommon butlers, miraculous engines Charles Babbage never dreamed of, and the impact of a war on the far side of the globe.