'Sherlock' Season 4 SPOILERS: Who Is Toby Jones' Villain on Benedict Cumberbatch BBC Show?

Without counting the one-off special Christmas episode last January, it's been nearly two years since the last time the world got to see Benedict Cumberbatch's consulting detective joined by Martin Freeman's John Watson -- but we're finally getting more soon! The two stars are currently filming season 4 of BBC's Sherlock, with Toby Jones cast as a villain -- but who?

Little to nothing is known so far about the fourth season of Sherlock, as its stars have been seen filming in different London locations lately; however, it seems there has been a leak in regards to the bad guy in the fourth installment of Sherlock Holmes' modern-day adventures.

Cultbox reported earlier this week that Jones, whose casting in this season's second episode was announced weeks back, would be playing Culverton Smith, a character that first appeared the 1913 short story The Adventure of the Dying Detective.

Originally, sir Arthur Conan Doyle described the character as "small, frail, twisted" as well as with "a double chin... high bald head... and menacing grey eyes," which sounds right up Jones' alley, particularly considering he's played the Nazi Marvel villain Arnim Zola since Captain America: The First Avenger.

In the original story, Sherlock suspects Smith of killing his nephew, which in turn prompts him to poison the detective by sending him a box contaminated with a strange illness. Of course, Sherlock tricks Smith into thinking he's gravely ill, until he confesses to the crime and it's revealed Holmes has been healthy and plotting the entire time.

Den of Geek reports that, while there has been no official word on whether Jones will in fact be playing this classic Holmes baddie, Sherlock showrunners Steven Moffat and Mark Gatiss recently shared how thrilled they are to have the Emmy-nominated actor joining the show.

"Delighted to have Toby Jones on board, bringing to life one of Doyle's finest villains," said Moffat first, with Gatiss adding 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!"

The two Sherlock main actors have turned into superstars since the show began in 2010, with Freeman starring in Peter Jackson's The Hobbit trilogy as well as being part of Fargo; meanwhile, Cumberbatch has turned into one of the busiest actors in Hollywood, from a Star Trek villain to an Oscar nominee and soon a Marvel superhero on Doctor Strange. Because of their success, it's a almost a miracle they can even make time for a new Sherlock season.