The NCIS team investigates the murder of a petty officer who was in town to help a refugee family being recruited by terrorists. Also, Wade works on the special election campaign for Mayor Zahra Taylor that takes place during Mardi Gras.

While NCIS investigates the murder of a Navy intelligence officer killed during a conference for foreign diplomats, the key witness cozies up to Sebastian. Also, Pride has some trouble adjusting to his new position at the agency.

NCIS investigates the disappearance of a Navy entomologist after a deadly shooting at a research lab. Nero, with Naval Intelligence, joins the investigation when the team discovers a rare and deadly virus was also stolen.