NCIS: Los Angeles season 12 episode 18 marks the return of Linda Hunt as Operational Manager Hetty Lange. She hasn't been seen through most of the current installment and Nell Jones (Renee Felice Smith) took over some of her roles.

NCIS: Los Angeles season 12 episode 18 will serve as the season finale, which comes with the title "A Tale of Two Igors." Hetty's return could bring closure to one of the biggest storylines in the current installment and this could impact the story moving forward.

Throughout the early run, Nell has been struggling to fill up Linda's role. Now, the latter may offer encouragement to the team's intelligence analyst. There are also speculations that she might be preparing to replace her as the new operational manager.

The synopsis of NCIS: Los Angeles season 12 episode 18 didn't provide more details as to what would be the role of Hetty, aside from confirming that she's returning. In addition, it remains to be seen whether or not she's coming back in the already-renewed season 13.

Over the past few seasons, there have been rumors that Hunt is departing from the police procedural drama at some point. Her appearance became fewer than before, which indicates that the series is already setting up her exit in the future.

Moreover, Nell has been doing most of her jobs and she could eventually take over Hetty's job. But, for now, there is no official confirmation that Hunt is leaving the series. There's still a possibility that she'll make an appearance in the next installment.

As for what else viewers can anticipate in NCIS: Los Angeles season 12 episode 18, Marty Deeks (Eric Christian Olsen) finds himself in deep trouble. He was kidnapped by one of the associates of Kirkin (Ravil Isyanov), who needs his help.

The team, on the other hand, will be investigating the shooting of a militarized dolphin equipped with a Russian microchip. In addition, more stories are coming for other characters, such as Eric Beale (Barrett Foa) making Nell an interesting offer.

Aside from the rumored departure of Hetty, there is also speculation that Smith is leaving her Nell role. Although she is a potential replacement for the position of Hunt's character, there are hints that she's planning to leave the department and go somewhere else.

The promo teased that the character was forced to make a difficult decision. Kilbride (Gerald McRaney) asked her to choose either to resign from the department or sign on to the operational manager's old post. It's yet to be seen what would be her final decision as the series may leave a cliffhanger leading to season 13.

NCIS: Los Angeles season 12 episode 18 airs on Sunday, May 23, on CBS.