The NCIS: LA team is called in to determine if the computer system that controls Russian missiles is at risk after Eric overhears his friend, a computer systems expert, being attacked during online game play. Meanwhile, Kensi is shocked when a familiar face from her past shows up in Afghanistan.

When the NCIS: Los Angeles team investigates a case involving a former marine who is being tracked down by members of al Qaeda for embezzling money from Iraq, Hetty assigns Nell to join Deeks in the field. Meanwhile, Eric is given a new partner in Ops.