The squad will work closely with the National Security Agency in the upcoming episode of "NCIS: Los Angeles."

In the episode titled "Tidings We Bring," the synopsis (as per Spoiler TV) reveals that the NCIS will be tapped to investigate the mysterious disappearance of a Navy Lieutenant Commander. Before he went missing, the officer was known to be working with the NSA. He was in charge of tracking down foreign cyber threats.

The NCIS will not leave any stone unturned in this investigation, as there could be more at stake. The squad needs the NSA's cooperation though since only they can say what the missing man was working on before he disappeared. Callen (Chris O'Donnell) and Deeks (Eric Christian Olsen) will team up for this case, while Sam (LL Cool J) will work with Callen's girl Anna (Bar Paly). Will they find the commander alive?

Meanwhile, the clock is ticking for Hetty (Linda Hunt). She is no closer to finding out the identity of the mole on her team. The culprit has so far evaded every trap they set out for him. Hetty knows she will have to resign if she cannot find the mole in time. She and the Navy secretary have a deal and her deadline is right around the corner. Her agents have been scurrying around, trying to find any clue that will point to the spy. Nell (Renée Felice Smith) did a great job last episode, when she got their remaining informant to talk. Still, they were a tad too late to save the woman who might be the key to the whole thing.

The new episode is also expected to see the team preparing for the holidays. There has been some good news regarding Kensi's (Daniela Ruah) condition. It is only a matter of time until she returns to the field. Hetty, however, insists that Kensi should be at 100 percent before coming back. It may be frustrating to the agent, but she knows her boss is correct on this one.

"NCIS: Los Angeles" season 8 episode 11 airs Sunday, Dec. 18 at 8:30 p.m. EST on CBS.