The production for "Sherlock" season 4 will officially commence this spring, bringing fans closer to new episodes featuring the greatest fictional sleuth in history. That being said, it looks like actor Benedict Cumberbatch will be back as Sherlock Holmes as early as next year.

The cast and crew of "Sherlock" will be back on set next month. Cumberbatch and Martin Freeman, who plays Sherlock's right-hand man Watson, have been so busy and sought-after in the recent years that their packed schedule had no room for filming the BBC drama.

But the calendar is now clear for the actors and they are now ready to be back as the beloved mystery-solving duo. The script for the three new "Sherlock" season 4 episodes was recently completed by show creator Steven Moffat.

According to spoilers, "Sherlock" season 4 will be packed with meaty plotlines that have been waiting to be dealt with. To begin with, the third Holmes brother will allegedly be revealed in the upcoming season.

There's no confirmation about this yet, but this certainly is one of the biggest lingering mysteries on the show. Fans have been trying to figure out how it all goes down and their wish is for Sherlock and Mycroft's brother to be played by "Avengers" star Tom Hiddleston.

Unfortunately, there are no details about this casting except for the fact that majority of fans want it to happen. Hiddleston, however, is a very busy man as well. He's the star of the new British-American television serial "The Night Manager" and also has two films in the works "Kong: Skull Island" and "Thor: Ragnarok."

For now, it looks like viewers will have to wait until next year to know if "Sherlock" season 4 will introduce the third Holmes brother. While at it, fans will also have to speculate whether or not Andrew Scott will be back as Moriarty in the series.

In the final seconds of "Sherlock" season 3, fans will remember Sherlock's rival showing himself in a static image saying, "Miss me?" It remains to be seen if this is an indication of his return after purportedly killing himself in season 2.

"Sherlock" season 4 is expected to premiere early 2017.