Fans of the CBS Sherlock Holmes-based TV series should be in for a good treat this spring 2018, as the sixth season of "Elementary" is officially set to premiereon April 30.

However, avid watchers of the show will have to adapt to a new time slot, as the upcoming season is slated to air Mondays at 10 p.m. EDT. This time slot was occupied by "Scorpion," which recently concluded its season 4.

"Elementary's" sixth season will be an extended one with 21 episodes as opposed to the originally proposed 13 episodes, after CBS ordered eight additional episodes.

Followers of the TV series will also see a new addition to the cast. Desmond Harrington, an American actor known for his role as Detective Joey Quinn in Showtime's series "Dexter," will be joining the show as a regular.

Harrington will play the role of Michael, a recovering addict who might prove to be integral in Holmes' strained relationship with his partner, Joan Watson.

However, Michael's character is more complex that it seems.

"Michael is somebody who's in recovery and someone who wants to be helpful. But as is so often the case, the deeper we get into the season, we'll see there's a bit more going on with Michael than meets the eye," said Rob Doherty, executive producer of "Elementary," in an interview with TV Line.

This hint by Doherty gave fans a lot to speculate about the plot of season 6. Such include Holmes' recurring hallucinations, talking robotically to a woman, who later turned out to be his dead mother.

The correlation of Holmes' hallucinations could be traced back to his brain scans, which was also revealed in the season finale.

Asked about this mental issue, Doherty said that for Sherlock, "Working as a detective is about to become a lot more complicated for him and life in general."

Catch the "Elementary" season 6 premiere on Monday, April 30, at 10 p.m. EDT on CBS.