'Down the Strand the lamps were but misty splotches of diffused light which threw a feeble circular glimmer upon the slimy pavement'. Whilst the seamy streets of London drown in a sea of smog, Sherlock Holmes sinks into a cocaine-induced melancholy, until Miss Mary Morstan presents him with a most intriguing case. A terrible death, an unknown benefactor, stolen treasure, and a secret pact between criminals stretching back to a mutiny-torn India, lead Holmes into an epic pursuit of the truth...