The unpublished story of Sherlock Holmes' greatest rival, Moriarty! Before becoming Sherlock's adversary, Moriarty fought against the unjust system of social discrimination in London, ensuring that the corrupt aristocracy would pay for its actions. But even the best-laid plans can go awry. Will Moriarty's dream of a fairer and equal world turn him into a hero... or a monster?

The crisis is ready to unfold when William Moriarty finally confronts the fake Jack the Ripper, who is actually a group of men tarnishing the good name of his childhood mentor to sow fear and discord in London. After William and his gang neutralize the fraudsters, Sherlock Holmes arrives to investigate.

Although he soon understands the truth behind the murders of Jack the Ripper, Scotland Yard remains in the dark. In a desperate attempt to resolve the situation, the head of the Yard arrests an innocent man and accuses him of the murders! Lestrade and the Moriartys are determined to shed light on this false arrest before the man is hanged. While Lestrade seeks Holmes' help again, MI6 sends its latest graduate...