Joan Watson will be tapped to phone up some old connections to solve a new case in "Elementary" season 5.

An episode of the upcoming season will feature another classic character from the book of Sir Arthur Conan Doyle, which is the basis of the show. Titled "The Illustrious Client," the book introduces Shinwell Johnson, which will be played by "True Blood" star Nelsan Ellis. In the show, Johnson is one of Watson's former patients when she was still working as a surgeon.

The most intriguing thing about the new character aside from the fact that he previously had a run-in with the law is that he belongs to the same league as some notorious personalities in the mafia. Apparently, his connections will make him one of Sherlock's most valuable sources in handling the case.

In other news, the 100the episode of "Elementary" season 5, titled "Henny Penny the Sky is Falling," will feature Owain Yeoman as an old acquaintance of Sherlock from her days in the boarding school. According to reports, the "Mentalist" actor will take on the role of a very fun and colorful character who will help Sherlock solve a new case.
"Elementary" showrunner Rob Doberty previously teased the case to have "a mystery on top of a mystery."

"The episode revolves around the murder of a man who was looking for better and more efficient ways to identify what are known as Earth-killer asteroids," he said.  "There's mystery on top of mystery as to why anyone would want to kill someone who might be able to help NASA locate and divert small planetoid hurdling towards Earth," he said.

The new season of "Elementary" premieres on October 2, 10:00 P.M. on CBS.