It is June 1884, a grey period for both the weather and Sherlock Holmes' mood. A lack of compelling cases has left him bored and close once again to the dull embrace of the needle. Less than a month earlier, however, he had astonished Inspector Lestrade and everyone around him by solving no less than six crimes in consecutive days.

At the eleventh hour, Inspector Gregson arrives, with the promise of an impossible crime to solve. A murder has shattered the bucolic peace of the sleepy arable farmlands of Bedfordshire. The owner of a small stately home has been brutally killed while hosting a dinner party. But what and where is the murder weapon?

What follows is an epic, sweeping tale. From England to Africa, from poverty to wealth, the story spans decades. Hardship and friendship are followed by betrayal, deception and murder.