After two seasons of searching, “NCIS: Los Angeles” has a line on the mole. An enemy at the gate is one thing, but once that foe slips inside the walls, the war becomes a pitched battle of subterfuge and stalking horses. While that’s the reality Hetty’s (Linda Hunt) team has been living with as of late, it seems the double agent’s time is nearing an end.

Episode 10 plot revealed!

Ever since the mole targeted Sam Hanna’s (LL Cool J) family, they’ve been No. 1 on the OSP’s most wanted list. Their investigation runs in fits and starts, cooling off every time "NCIS: LA" stumbles upon a new lead. Luckily, “Sirens” will change the game.

“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,” CBS teased. “Also, Nell visits a prison to interview an inmate withholding information on the department’s leak.”

Sam has a keen eye for detail, but Nell (Renee Felice Smith) is an interrogation wizard in her own right. While the former Navy SEAL had no trouble sussing out Carl Brown’s true motivations in “Ghost Gun,” the former NCIS employee will have to deal with the Ops denizen instead. Now that we know Carl was merely a pawn, it’s time to meet the woman who so willingly sacrificed him.

“The reveal is that obviously it's a much larger storyline than just [Carl],” Eric Christian Olsen (Deeks) told TV Guide.

“He kind of sold himself as a one-off, and of course, like all things, once you start pulling a thread, you reveal that the sweater is much larger and there's a looming conspiracy at hand. So we get into all that stuff in the next few episodes.”

Next time on ‘NCIS: LA’

Viewers will have to wait until Nov.

27 for “Sirens.” In the meantime, the return of Callen’s (Chris O’Donnell) father will shed more light on G’s family. Perpetually unattached, the former orphan will soon find out what it’s like to live under the same roof as dear old dad. That’s right, folks; Callen is getting a roomie. While it might not happen this week, Nov.

20’s “Glasnost” will certainly lay the groundwork.

Find out more when “NCIS: LA” airs Sundays at 8 p.m. ET on CBS. Click the video below to see a preview for the series’ next episode.

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