Holmes and Watson's new careers as consultants for Scotland Yard in London take them inside the tabloid journalism industry when a model is the victim of an acid attack.

Holmes and Watson try to work a stateside investigation from London when someone close to them is gravely wounded by an unknown perpetrator in the U.S.; Holmes' stateside legal trouble threatens to derail their efforts.

Holmes takes extreme measures to gain legal re-entry into the U.S.; Watson helps the NYPD investigate a murder at a storage facility that caters to wealthy clients with items they want hidden from customs agents.

After an explosion at a traffic stop, Holmes and Watson must determine whether the attack was a terrorist attack; Holmes and Watson suspect there is more for them to discover regarding the recent attack.

Holmes and Watson must find the connection between three unrelated murders. Billionaire Odin Reichenbach suspects he is being threatened by someone in his own company and hires Holmes and Watson to find the perpetrator.

Cassie Lenue seeks the help of Holmes and Watson in solving a murder but they believe she has an ulterior motive.

In the wake of a sculptor's murder in New York, Holmes and Watson must determine whether a long dormant serial killer has resurfaced; Watson suspects Holmes is keeping something from her.

Holmes and Watson's foe, Odin Reichenbach, asks them to test his new crime prevention system; tasked with investigating someone the program predicts will commit a crime, they worry Odin will take drastic action.

Holmes and Watson reluctantly enlist the help of Holmes's father to publicize the crime prevention system of Odin Reichenbach.

Tech billionaire Odin Reichenbach inadvertently provides Holmes and Watson with a lead that could give them evidence that brings him to justice.

In the series' finale, Holmes and Watson battle with tech billionaire Odin Reichenbach and receive word of their old enemy and Sherlock's former love, Jamie Moriarty.