The next episode of "Rizzoli & Isles" season 7 titled "2M7258-100" will follow Jane as she goes undercover in the country jail.

In episode 8, the female detective will go undercover in a prison as she tries to help the police track down a criminal who's on the run after committing murder. Posing as one of the convicts behind bars, Jane will try to find out as much information as she can about the suspect.

According to Catermatt, Jane may have to make the best use of her acting ability as she accomplishes her mission. It is going to be a very dangerous mission, so the faster she identifies and apprehends the murderer, the better for her.

The upcoming episode marks the 100^th episode of the TV series, and it is set to feature an important guest star.

Executive producer Jan Nash revealed that Sharon Gless has agreed to make an appearance at Harmon's request. The two of them met by chance while dining at a restaurant in Los Angeles. According to reports, Harmon requested Gless to join them for their 100^th episode, and Gless cordially agreed.

Jane will reportedly meet the two-time Emmy Award-winning actress inside the prison.

Nash further revealed in his interview with KSiteTV that viewers should expect some wonderful performances in the upcoming episode as Harmon did a great job in its direction.

Asked about the series' ending, Nash said, "It's been very emotional."

"Rizzoli & Isles" season 7, episode 8 airs on July 25, 9:00 P.M. on TNT.