The team busts crooked banker Mara at a Christmas party. Then Deeks and Kensi serve their new loco moco to Sam and Callen at their bar. They debate whether Hetty is thinking about retiring. Kensi asks Sam and Callen if one of them would take over after Hetty leaves, but they both beg off. Army CID Special Agent Steve Evans asks Eric and Nell to gather the team because he believes L.A. will be the target of a terrorist attack. Evans thinks that Ethan Peretz will download a computer virus in L.A. or Chicago. Sam encourages Callen to take over for Hetty when she retires. Eric admits to Nell that he enjoyed being a civilian. Sam tells Callen that he would like to mentor a young agent. Kensi and Deeks talk about having children. Eric and Nell disect their relationship as he prepares to move out so Nell's sister Sidney can move in. Sam had considered moving to the Department of Justice to be partnered with Lance Hamilton. Nell tells Eric that her mother isn't getting any better. Czech mercenaries are working with Peretz. Sam tells Callen he's moved past the dark place he was in after Michelle died. Sam explains his plan for improving the team after Hetty leaves to Callen. Kensi tells Deeks that she's ready to have a baby. Nell and Eric locate Peretz and call the team. Peretz is targeting LAX. The team and Evans confront Peretz and his shooters. They stop Peretz before he can upload the virus. Nell tells Eric that she doesn't want to analyze their relationship but to keep it as it is. Callen tells Sam that he's going to look for Anna. They have no ride back after the shootout and have to call an Uber.