Following a fall from grace in London and spending time in rehab, the eccentric Sherlock Holmes takes residence in Manhattan, New York, where his wealthy father assigns him a "sober companion", Dr. Joan Watson, to help with his rehabilitation.

Dr. Watson was a successful surgeon until she lost a patient. However, the eccentric Holmes is nothing like her other clients. As part of a post-rehab regimen he designed himself, Holmes resumes his work as a police consultant in New York, and Watson is along for the ride.