Sherlock's and Joan's new careers as consultants for Scotland Yard in London take them inside the tabloid journalism industry when a popular model is the victim of an acid attack. As Joan grows increasingly homesick for New York, Gregson is wracked with guilt over his unresolved rift with his former consultants.

Sherlock and Joan try to work a stateside investigation from London when someone close to them in the U.S. is gravely wounded by an unknown perpetrator. Sherlock’s stateside legal trouble threatens to derail their efforts.

Sherlock takes extreme measures to secure his return to New York when he leans on his father’s disreputable connections to aid his legal re-entry into the United States. Joan helps the NYPD investigate a murder at a storage facility that caters to wealthy clients with items they want hidden from U.S. Customs.

An explosion at a traffic stop puts Sherlock and Joan on two separate tracks of investigation as they try to determine whether the attack was gang-related or a terrorist attack. Sherlock and Joan suspect there is more for them to discover regarding the recent attack on someone within their inner circle.

Tech billionaire Odin Reichenbach hires Sherlock and Joan to investigate a personal threat he suspects originated from within his own company. Sherlock and Joan search for a motive behind three seemingly unconnected murders.

Tech billionaire Odin Reichenbach presents Sherlock and Joan with an extraordinary offer to help him with a program that can predict future crimes. Sherlock and Joan assist Bell when he tries to prevent a future crime of his own, as he races to locate a fellow NYPD officer planning a sniper shooting.

Sherlock and Joan investigate the murder of a criminal who made his living by stealing from other criminals. When Gregson resumes leadership of the precinct, he suspects his interim replacement is responsible for one of his best detective’s suspicious departure.

Sherlock and Joan search for an ulterior motive when a brilliant young criminal they helped put in prison, seeks their help in solving a murder.

Sherlock and Joan work to determine if a long dormant serial killer has resurfaced in the wake of a sculptor’s murder in New York City. Joan suspects Sherlock is keeping something from her regarding tech billionaire, Odin Reichenbach.

Sherlock and Joan receive a shocking request to collaborate from Reichenbach, who asks them to test his new crime prevention system. Tasked with investigating someone the program predicts will soon commit a crime, the duo worries Reichenbach will take drastic action before they conclude their inquiry.

Sherlock and Joan join forces with Holmes’ father, Morland to enlist his vast criminal network to help disassemble Reichenbach’s crime prevention system.

Reichenbach inadvertently provides Sherlock and Joan with a lead that could give them evidence that brings him to justice.

Amidst Sherlock and Joan’s battle with tech billionaire Odin Reichenbach, the investigators receive word of their old enemy and Sherlock’s former love, Jamie Moriarty.