Kensi and Deeks go undercover at a decommissioned nuclear power plant as the team investigates the radiation poisoning of a Gunnery Sergeant moonlighting as a security guard there.

When Kensi and Deeks announce to the team they are moving in together, coincidentally, Hetty assigns them to protection detail for Jack, Kensi's ex-fiancé, who is in possession of a list containing important contacts in Afghanistan that people are willing to kill to get their hands on.