A commoner is chased down by a hunter and his dogs before being shot. The ocean liner Noahtic begins its maiden voyage and Count Blitz Enders, an openly arrogant noble, heavily criticizes that commoners are allowed aboard. Days previously, William shared his plan to slowly remake society by plunging London into an era of crime, all while committing murders designed to educate commoners in exactly how the nobility have been abusing them, starting with Blitz.

Moriarty pretends to believe Blitz’s lie that he killed Thomas in self-defense and offers to cover up the crime.

Military Intelligence Service Director Mycroft orders Albert to recover classified papers that could rock the nation, and kill the woman who stole them. Sherlock is hired by the king of Bohemia to pursue Irene Adler, who threatens the king’s wedding plans.

A series of murders is being carried out by someone claiming to be Jack the Ripper. In response, a vigilante group of the town's poor confronts Scotland Yard while William and the real Jack scramble to uncover the true culprit's aims and foil their plans.

John introduces Sherlock to Mary, his fiancée. A stunned Sherlock realizes that Mary has another concern. She produces six pearls, detailing their connection to her missing father. She asks Sherlock to look into the matter, but is holding something back.

William aims to complete his plan with his death, as Albert and the others each carry out their roles. Meanwhile, Sherlock deduces William's true reason for having him vanquish the Lord of Crime. Overlooking London, the pair face each other one last time.