NCIS: Sydney will do whatever it takes to crack the case of a rogue assassin on the run during NCIS Special Agent DeShawn Jackson's chaotic first day as boss.

When a young girl finds the body of a former U.S. Navy officer floating in the harbor, the team is led to an 18th-century sailing ship hosting a pirate-themed wedding, where DeShawn and Evie go undercover to investigate. Meanwhile, Mackey and JD are pulled in to prevent a potential tragedy on the harbor that could rip the U.S.-Australia alliance apart.

When the body of a long-missing U.S. Naval engineer is discovered buried in concrete, the team enlists Doc Roy's old friend to assist in the investigation.

NCIS: Sydney is thrown into the murky world of online conspiracies after a car owned by a U.S. Navy cyber engineer explodes just as her teenage daughter was about to take a driving lesson.

When a petty officer is found cuddled and frozen, it leads the team into a twisted underworld of seafood and sex trafficking.