"Sherlock" season 4 has already begun production primarily in Cardiff and it is speculated that the first episode has already been completed. According to a new report from the Huffington Post Morocco (via CultBox), the second episode will be filmed in Marrakesh, Morocco, indicating a sudden shift in the series' primary setting.

It is undetermined if the Morocco scenes will be used for episodes 2 and 3 or if they will be inserted as well into the premiere episode.

Toby Jones has been cast to portray the main villain of the season and his character, according to a report from Deadline, is said to be based on one of author Arthur Conan Doyle's finest villains.

Unfortunately, the exact identity of this villain and what scheme they have brewing remain a mystery. Despite the villain beng based on one of the characters from Doyle's written work, the series is a modern retelling and the Morocco setting does not match up with anything from the "Sherlock Holmes" short stories.

It is speculated by fans that Sherlock (Benedict Cumberbatch) and Watson (Martin Freeman) will need to head to Morocco to take down the villain or at least one of his main plans but there are speculations that this is where the British government sends Sherlock given that he was banished at the end of season 3. 

Morocco may also be the area where Jones's character resides or operates. The BBC has yet to issue any official teaser trailer or announcement and neither Jones nor the other cast members have given any official clues, therefore the information about Jones and the Morocco setting is still considered pure speculation. 

"Sherlock" season 4 is expected to premiere by Christmas in the U.K. and this may follow with a New Year's Eve or early January premiere in the United States. The BBC has yet to announce an official premiere date.