The fourth season of “Sherlock” is a long way but thanks to the casting of some new faces, fans get a taste of what’s to come.

Express reports that actor Sacha Dawan has been cast in a mysterious role for “Sherlock” season 4. Although no other details were revealed about the character, the website details that the star will play a character named AJ.

Whether AJ is indeed the name of the character or just an alias is a mystery. Also, the series is known for featuring a different case per episode. This makes AJ a potential player in one of those cases. He could be a client of Sherlock’s, or a perpetrator. As far as speculation goes, he can be anything.

New ‘Sherlock’ characters

Meanwhile, a recent article from Den of Geek shares other stars joining “Sherlock” season 4. Toby Jones, Daniel Hoffman-Gill, and James Holmes were listed as having respective involvements with the show come January 2017.

Hoffman-Gill’s and Holmes’ characters at this point are quite shrouded in mystery. It was detailed, though, that Holmes will play a character named “Passenger”.

However, Jones’ character appears to be the most important of all these new faces. As per Den of Geek, Jones will play Culverton Smith. The website describes the character as follows:

Culverton Smith‘s grudge against Sherlock Holmes began when the latter suspected him of his nephew’s murder. Resolving to rid himself of this troublesome detective, Smith infected a spring-loaded pin with a deadly disease and posted it to 221b Baker Street with the intention of killing Holmes.”

Season 2 finale all over again?

Still, the website elaborates that Sherlock Holmes detects the threat to his life. He then cooks up a plan where he pretends to be infected with the disease. However, before he can convince Smith, he must first make Dr. Watson believe the idea.

If the show creators follow this story line, it will be reminiscent of when Sherlock Holmes faked his death to defeat Moriarty‘s threats. However, he hurt Dr. Watson’s feelings in the process. Will the friends face another strain in the relationship?

Viewers can find out the whole truth when “Sherlock” season 4 returns on air in 2017.