Autumn, 1900. The lives of Sherlock Holmes and John Watson are in a state of change. The doctor has moved out of Baker Street, waiting anxiously to marry his new love, the American actress, Genevieve Dumont. Holmes has been left restless and fretful, eager for mystery and distraction.
A secret code and a brutal murder promise to bring the two men back into each other’s orbit. But there is more to the investigation than first appears to be the case. Something greater seems to be at work, moving dextrously behind the scenes: a force in the London underworld known only as The Seamstress of Peckham Rye.