When an anonymous tip leads to the discovery of a young Marine's body at a chilling crime scene, Randy believes it could be connected to a previous case where a coin was left in the victim's throat.

When Lala's favorite CI is shot, the team joins forces with Oceanside PD to determine who was behind the attack; Franks visits his brother Mason at the compound; Gibbs' relationship with Diane is tested when she gets a job in Los Angeles.