Actor Robin Williams will guest star on the upcoming 200th episode of “Law & Order: SVU,” trade paper Variety reports.

The episode Robin Williams makes an appearance in will air April 29, the first Tuesday of the May sweep, Variety reports. Neal Baer, executive producer of “Law & Order: SVU,” promises Williams’ segment has a “powerful and complex” storyline.

“We are thrilled that one of the most talented and versatile actors around will be starring in this powerful and complex special 200th episode,” Baer said. “We can't imagine anyone else doing this role.”

Williams will portray an engineer whose life has gone off-track following a tragedy, according to the trade paper. He develops a deep distrust of authority and begins to encourage others to do the same.

The script was written by Baer and “SVU” co-exec producer Amanda Green.

Williams’ appearances on television series have been rare. The 1980s sitcom “Mork & Mindy” was a breakthrough for the 55-year-old actor, who then moved on to movies, many critically acclaimed and very successful at the box office.

His performance in 1987’s “Good Morning, Vietnam” earned Williams a Golden Globe Award and an Academy Award nomination. He received two more Academy Award nominations the following years, for his roles in “Dead Poets Society” (1989) and “The Fisher King” (1991).

In 1998, he won an Oscar as Best Supporting Actor for his role as a psychologist in “Good Will Hunting.”

His guest appearance in 1994 on NBC's “Homicide: Life on the Street” led to an Emmy nomination for the actor.

NBC's “Law & Order: Special Victims Unit,” created by Dick Wolf, debuted in 1999 as a spin-off of the crime drama “Law & Order” and has now entered its successful ninth season. It stars Christopher Meloni and Mariska Hargitay as two detectives of the Special Victims Unit of the New York Police Department.

The cast also includes Richard Belzer, Diane Neal, Ice-T, Adam Beach, B. D. Wong, Tamara Tunie and Dann Florek.