Sherlock Holmes - The Immortal Man

The year is 1894 and Sherlock Holmes is summoned to an art gallery in Covent Garden, where dozens of dead visitors lie before a painting of the Immortal Man.
How could someone kill all the visitors to the exhibition at once, and why would they even do such a thing? Holmes and Watson soon get on the trail of a mysterious figure in black, who is impossible to catch thanks to his incredible speed and agility.
Not long after, the horribly mutilated body of a servant of a Russian Grand Duke, who is currently staying in London, is found in an infamous slum - is the same perpetrator responsible for this too? But what connects these two crimes and is there any connection to the suicide of an unpopular teacher at a remote boarding school?
Thus begins a case that reveals how dark shadows sins from the past can cast, and tests both Holmes and Watson to the limits of their powers.