After announcing an extended season 5, TNT announced that "Twin Peaks" star Sherilyn Fenn will appear as a guest star in an upcoming episode of "Major Crimes."

TV Line reported that Fenn will portray the role of the aggressively controlling mother/manager of a young actor named Chris Walker, who mysteriously died of overdose in the-still untitled episode 8 of "Major Crimes" season 5, which is scheduled to air on Monday, Aug. 15.

According to the report, Andy Flynn (Tony Denison) and Michael Tao (Michael Paul Chan) will try to unravel the reason behind the mysterious death of the young actor, who is known for starring as the lead actor in a TV series titled "Gold Storm."

The episode where Fenn will appear will also feature "Gone Girl" cast member Missi Pyle as Chris' older, party-enthusiast widow, as well as "Mad Men" alum Stephanie Courtney as the doctor who appears to be the celebrities' source of addictive prescription drugs.

Meanwhile, the Major Crimes division will help the FBI in searching for a wanted terrorist in episode 3, titled "Foreign Affairs."

According to the synopsis for the upcoming episode that airs on Monday, June 27, "After an ISIS-inspired attack against a member of the U.S. Armed Services, the FBI asks for Captain Raydor's help in finding a terrorist, as Major Crimes joins the Bureau in a race against the clock before the terrorist can strike again."

Series creator James Duff also teased who among the members of LAPD's Major Crimes Division will have the most number of challenges in the coming episode of season 5.

According to Duff, the Civilian Surveillance Coordinator Buzz Watson (Phillip P. Keene) will have a lot on his plate to find out who killed his father and uncle in the previous seasons of the series.

"That's the story that plays out through the season, and everybody gets involved in it," the series creator said in an interview with TVLine. "I would also say that, as the season progresses, Sharon ends up having a great deal on her plate in terms of where the eventual power lies inside the department. I can't say more than that on that issue, but she does end up with sort of a big problem."