Benedict Cumberbatch is presently in London, and while shooting for "Sherlock" season 4, he mentioned that he was "gobsmacked" by the show's success.

"The gob-smacking thing about it is that people who have been icons to me forever have been coming up to me to say much they adore [the show]," Cumberbatch said. "When Meryl Streep told me, 'I love Sherlock, I thought, 'That's so wrong!'"

Cumberbatch told Radio Times last year that he'd "love to keep aging" with his Holmes character.

Although little to nothing is known about the latest season of "Sherlock", yet an alleged leak has thrown some light on Sherlock's adventures.

According to Cultbox, Toby Jones, whose casting was announced weeks ago, would be playing the role of Culverton Smith, a character who first appeared in 1913 short story named "The Adventure of the Dying Detective."

The 49-year-old British actor's online CV has now been updated to confirm that he will be playing Culverton Smith in the episode.

Sir Arthur Conan Doyle has originally described Jones' character as "small, frail, twisted" and "a double chin... high bald head... and menacing grey eyes", which does match up to some extent with Jones' physique and appearance.

However, although there has been no confirmation as to what Jones' role will be in the show, the showrunners Mark Gatiss and Steven Moffat has recently shared their excitement on having the Emmy - nominated actor on board.

"Delighted to have Toby Jones on board, bringing to life one of Doyle's finest villains," said Moffat.

Additionally, Gatiss added that they were "thrilled to welcome one of our finest actors to the "Sherlock" family. I know Toby will embrace the part with true relish!"

So, it seems that the upcoming season of "Sherlock" will have a lot of mystery in addition to the adventure, and viewers will have to actually stay tuned to catch more information on Jones' character.