Following the murder of a Marine, Tony and Ziva join Ziva's longtime friend and mentor in Columbia in a search for a missing Marine Lieutenant and Navy Chaplain. Meanwhile, Jimmy Palmer decides who will be his best man.

The NCIS investigation of a fire on a Navy vessel reveals evidence that elevates security at all U.S. Navy facilities worldwide. Meanwhile, DiNozzo and Ziva travel to Italy when an explosive device is found hidden on a Navy ship.