In London at the end of the 19th century, the thick fog of the Industrial Revolution concealed countless evils.
When Scotland Yard was helpless about the bizarre murder, the lights of 221B Baker Street came on again.
Arthur Pendleton, a genius mechanic with a withdrawn personality and a firm belief that "everything is numbered", took his roommate Dr. Wilson, who had just returned from the war, into this bizarre world.
From the oil-oozing corpse in the secret room to the perfect alibi created using steam power; from the curse in the noble manor to the serial disappearances in the slums.
There are no ghosts and gods, only carefully designed tricks.
Watch how a genius mechanic uses a vernier caliper and absolutely rational logic to dismantle the craziest malice deep in the human heart.
"In this world of gears, crime is nothing but the friction of the machine."
