'NCIS: Los Angeles' season 8 episode 13 spoilers: NCIS members get arrested; Eric Christian Olsen teases conclusion to team's mole hunt

Planted evidence leads to the arrests of NCIS team members on the upcoming episode of "NCIS: Los Angeles" season 8.

Titled "Hot Water," next week's episode will see how the unit deals with a major complication. According to the official synopsis, the mole has, once again, compromised the NCIS team after planting evidence, which results in the arrests of Granger (Miguel Ferrer), Deeks (Eric Christian Olsen), Sam (LL Cool J), and Callen (Chris O'Donnell). To make matters worse, the issue happens on the day Undersecretary Duggan (Jackson Hurst) comes back for Hetty's (Linda Hunt) resignation.

The team's never-ending mole hunt is about to conclude, and one of the show's major cast members recently teased that it's going to be a huge revelation. "I'm arrested by Internal Affairs," Olsen told TV Line. "They find a body on Callen's front lawn. They find a body in Sam's trunk. They go after Kensi. Hetty is getting fired. And it all leads to a three-part culmination [starting later this month] that is the best version of everything. Characters come back out of the woodwork, there's peril, there's blood," he added.

While some "NCIS: LA" superfans may be able to deduce who the mole is, the actor shared that he wasn't able to figure out the mystery character's identity. "Some of the best fans may, but I didn't," Olsen added. "I don't know if anyone will see this coming," he went on to say.

After its recent time slot change, "NCIS: LA" appears to be doing good in terms of ratings. The veteran procedural is up 15 percent in the 18–49 demographic compared to its previous season. LL Cool J, who was also present during the interview, revealed that part of their success comes from the efforts of their new showrunner, R. Scott Gemmill. The rapper/actor mentioned that Gemmill is "doing a great job," adding that he approaches the show differently by "pushing the envelope a bit."

The eighth season of "NCIS: Los Angeles" airs every Sunday night at 8 p.m. ET on CBS.