Before he was Sherlock's rival, Moriarty fought against the unfair class caste system in London by making sure corrupt nobility got their comeuppance. But even the most well-intentioned plans can spin out of control--will Moriarty's dream of a more just and equal world turn him into a hero...or a monster?

After going missing for three years, Moran is plotting to assassinate Lord Balmoral, a man who threatens the Franco-British alliance. But when Louis tries to convince Moran that murder isn't the answer, his devotion to William leads to a violent confrontation! Meanwhile, Albert has been imprisoned for the crimes of the Moriarty family and takes it upon himself each night to serve penance for an even greater crime--the one he committed against William as a child.