The fourth series begins with the nation’s favourite detective, the mercurial Sherlock Holmes, back once more on British soil, as Doctor Watson and his wife, Mary, prepare for their biggest ever challenge - becoming parents for the first time.

Influenced by Guy Ritchie's film, the role of the heroine, Irene Adler, was also expanded on during the show. Her love affair with Sherlock Holmes is one of the series' main storylines. She will be played by actress Lyanka Gryu. Kavun has also said he only plans to use the motives of the original stories, and will recreate the stories almost from scratch. The series will also assume that Watson's descriptions of the crimes have been embellished. Later he will try to adjust reality to his fantasies. As an example, Holmes' famous pipe will be replaced by cigarettes. Unlike most adaptations of Sherlock Holmes, the Sherlock in this adaptation is younger than Dr. Watson by 15 years.

2015 film directed by Bill Condon

Eccentric consulting detective Sherlock Holmes and Doctor John Watson battle to bring down a new nemesis and unravel a deadly plot that could destroy England.

There is a new criminal mastermind at large (Professor Moriarty) and not only is he Holmes’ intellectual equal, but his capacity for evil and lack of conscience may give him an advantage over the detective.

Sherlock is back, but will things ever be the same again?

When a chance encounter brings soldier John Watson into Sherlock's life, it's apparent the two men couldn't be more different, but Sherlock's intellect coupled with John's pragmatism soon forges an unbreakable alliance as they investigate a series of baffling cases together.