Marine Lieutenant Colonel Sarah "Mac" MacKenzie (Catherine Bell) is returning for the next episode of NCIS: Los Angeles, but Callen (Chris O'Donnell) and Sam (LL Cool J) won't exactly be thrilled to see her again.
All is well at the start of "Code of Conduct," as Callen earns some ribbing from Sam about Callen's sudden interest in house hunting to be with Anna (Bar Paly). The easy, breezy tone doesn't last though: It's soon discovered that a commander has been accused by two SEALs of the unthinkable -- murder -- of prisoners and civilians in Afghanistan. Callen and especially Sam are reluctant to believe the accusers at first, but as evidence mounts, they're increasingly convinced they need to investigate. But it won't be easy -- especially with Mac guiding their steps.
Though she's as committed to finding out the truth as they are, she does make them aware of resistance to an investigation from inside the ranks. Turns out that the accused commanding officer has a high rank and connections within the government too, and Mac reminds Sam, a former SEAL himself, how difficult and complicated it can be to treat one of his own as a suspect. Still, he decides the truth is most important and heads to Afghanistan with Callen. Once there, Sam and Callen will find that the case is even more complex and dangerous than they could have imagined.
"How long do men stay loyal to other men? That's the question," executive producer Frank Military teased to TV Guide. "We're putting Sam right in the heart of that."
Because NCIS: Los Angeles is among the many shows that had their production schedules interrupted by the coronavirus outbreak, Sunday's episode will be the last for Season 11. It's not the finale producers originally had planned, but it certainly won't be lacking in impact. The episode is the first half of a two-part arc, too, so expect the ramifications of "Code of Conduct" to carry over into another season.
NCIS: Los Angeles airs Sunday at 9/8c on CBS.