Elementary - Season 2

Boom.

With Moriarty in prison, season 2 of Elementary focuses on another favourite from the canon's minor characters, Mycroft Holmes (played with insouciant flair by Rhys Ifans.) Leaner and less arrogant than the Mycroft of the books, Sherlock's restaurateur brother is the target of the deductionist's scorn for his idleness and lack of ambition, but strikes up a friendship - and more - with Joan, and proves to be significantly more than he seems (as should be little surprise to readers of the original stories or fans of Sherlock.)

While I am among those who fear the day that the series can no longer resist a romantic entanglement between Sherlock and Joan - a sure sign that the shark has been well and truly jumped - linking Mycroft and Joan is a very effective narrative gambit. It's pleasing enough just to see a female character who is capable of having a relationship which is casual, but has both a sexual and emotional component, but it also creates tension between the lead pair which exposes flaws in their partnership and reveals to Sherlock how much he values Joan without having him realise that he wuvs her.

Hey gang! It's Sean Pertwee!

Mycroft also brings with him some of Sherlock's baggage from England, including his old Scotland Yard oppo Gareth Lestrade (Sean Pertwee), a vainglorious plod who enjoyed the reflected glory of Holmes's work a little too much and commands none of the respect Sherlock displays for Gregson and Bell.

All that, and a season full of cases lifting more or less from the original canon. The arc-driven episodes this season have a tendency to suffer because they move away from the core dynamic which includes the NYPD characters, and from crime to espionage, a move which was not entirely successful in some of the later Doyle stories.