Enough Nemesis To Go Around – Holmes returns to America hoping to resume working with the NYPD, with a new apprentice in tow.
The Grand Experiment – Season 2 ends with the relationship between Holmes and Watson coming to a crossroads, but they agree to put their differences aside to help Sherlock’s brother Mycroft, who faces accusations of treason and murder.
Art in the Blood – Holmes and Watson come into contact with MI-6, the British intelligence agency, when a standard murder investigation turns out to have international and political implications. Meanwhile, in the wake of a crisis, Watson reevaluates her relationships with Sherlock and his brother, Mycroft.
Paint It Black – Sherlock is forced to partner with his estranged brother, Mycroft, to investigate a case with life-or-death consequences.
The Man With the Twisted Lip – A surprise visit from Sherlock’s brother Mycroft leads to discord between Holmes and Watson. Meanwhile, Sherlock and Joan investigate a missing person’s case that takes them into the world of unmanned aeronautics.
No Lack of Void – Holmes and Watson track a lethal toxin’s origin when a pickpocket dies of anthrax poisoning.
The Many Mouths of Andrew Colville – A serial killer who was presumed to be dead reappears and resumes his murderous ways, or so it appears.
The Hound of the Cancer Cells – Holmes investigates the murder of an influential cancer researcher and tries to determine whether the scientist’s untimely demise was linked to his latest cutting-edge invention that could have changed the face of modern medicine.
Ears to You – A man suspected of murdering his wife years ago receives a ransom demand for her safe return. Meanwhile, Lestrade overstays his welcome with Holmes and seems unwilling to leave.
The One Percent Solution – Holmes and Watson are forced to partner with Gareth Lestrade, Sherlock’s former Scotland Yard colleague, on a bombing investigation.