Sherlock Holmes (Jonny Lee Miller) and Joan Watson (Lucy Liu) are in for a surprise on the next episode of "Elementary." The detective duo will have to solve the murder of ex-convict Shinwell Johnson (Nelsan Ellis).

As revealed in the synopsis of episode 23 of "Elementary" season 5, titled "Scrambled," Holmes and Watson will be investigating the murder of the parole. Watson believes one of New York's deadliest gangs, Johnson's former gang, the SBK, is responsible for it.

To note, Johnson, shortly after getting out of prison, infiltrated the ranks of the gang in hopes of taking it down. Perhaps they found out his true intentions and ended him before he could succeed in his mission.

In the trailer of "Scrambled," Watson can be heard telling Holmes, "It was SBK. I'm sure of it."

Speaking to TV Line, executive producer Rob Doherty confirmed that the killer is one of SBK's members. He also teased that the murderer is someone who viewers have seen previously in the season.

Elsewhere in episode 23, viewers will see the eccentric detective Holmes behave erratically. His out-of-the-ordinary actions will be caused by a woman. The synopsis, however, spares the details about this mysterious lady.

On the other hand, Doherty shared a few details about this woman to Entertainment Weekly. He said, "We're going to meet a woman from Sherlock's past, someone we meet over the course of a support group meeting." The woman is a new character in the series. She will be portrayed by "Narcos" actress Joan Christie.

Although the woman is a new character, Holmes knows her well. Viewers will learn more about his relationship with the mystery woman in the upcoming episode.

"Elementary" season 5 episode 23, titled "Scrambled," premieres on Sunday, May 14, at 10 p.m. EDT on CBS.