Ep 4. Reznikov, N.

In NCIS: Los Angeles season 5 episode 4, titled "Reznikov, N.," the team investigates the murder of a retired CIA agent, who was also the father of one of their own, Nell Jones. As they delve deeper into the case, they discover that the victim had been investigating a dangerous group of Russian sleeper agents known as KROD, and had uncovered a list of their names and locations.

With this important information at stake, the team must race against time to stop these sleeper agents from carrying out their deadly mission. Along the way, they encounter a number of obstacles, including a corrupt CIA agent who is determined to keep their investigation under wraps, a treacherous Russian spy who will stop at nothing to protect the sleeper agents, and a ticking clock that threatens to run out before they can complete their mission.

As they navigate these challenges, the team must also grapple with their personal relationships and the emotional toll that comes from working in law enforcement. Nell in particular is forced to confront her feelings about her father's death and the role she played in his life, forcing her to make some difficult decisions about her own future.

Overall, NCIS: Los Angeles season 5 episode 4 is a thrilling and action-packed episode that explores complex themes of loyalty, love, and sacrifice. With its intricate plot and compelling characters, it is sure to keep viewers on the edge of their seats from beginning to end.