The upcoming episode of CBS' hit police procedural drama TV series "NCIS: Los Angeles" season 8 will likely leave the fans gripping the edge of their seats as the details rolled out for the segment tease an agent going on an undercover mission.

According to the spoiler reports for the episode called "Siren," the mission will center on the ongoing mole investigation. The issue has been a huge pain on their side ever since the season began and the show is expected to wrap it up in this segment. And one of the key players in this plot development is Renee Felice Smith's Intelligence Analyst Nell Jones.

Speculations indicate that Nell will try to infiltrate a prison system in order to extract some sensitive information regarding the department leak.

There's no telling what kind of secrets Nell will stumble upon in her operation but here's to hoping that it would finally help Callen (Chris O'Donnell), Hanna (LL Cool J), Hetty (Linda Hunt), and the rest of the crew, pin down the culprit who has been ratting them out.

The synopsis over at The Futon Critic also speaks of the case that the team will be facing this week. As specified in the summary, "after an unknown female assailant kills two men disguised as Sherriff's deputies in front of Callen's home, the NCIS team gets a new lead in the ongoing mole investigation."

The hour is also rumored to reveal the mystery sickness plaguing Granger (Miguel Ferrer). The latest word on the streets said that the actor would be leaving the show and his character will be written off with a sickness.

It is believed that episode 10 will unveil this particular detail as to what could be the cause for Granger's death or Ferrer's exit.

"NCIS: Los Angeles" season 8 airs Sundays at 8:30 p.m. on CBS.