After tracking Apollyon, a deadly underground spy network, to war-torn South Ossetia, Pride is separated from the team and faces grave danger. Also, in order to save Pride, the NCIS team must locate a mole who continues to feed information to Apollyon.

Pride must cut his vacation short when Hannah is suspended for breaking protocol during a joint investigation with the FBI.

Tammy must protect Rachel, a research-obsessed teenage girl, after her father is shot in their home, while the rest of the team searches for a motive.

As Pride directs the team to link Sasha to the recent attacks in New Orleans, he must help Connor come to terms with who his mother really is. Also, Carter and Tammy search for a stolen highly trained military dog, and Pride and Rita make an important decision about their wedding.