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.

The team 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 murdered and frozen, it leads the team into a twisted underworld of seafood and sex trafficking.

The suspected suicide of a former U.S. Navy SEAL leads NCIS: Sydney to a wellness retreat to investigate a group of his fellow former SEAL buddies.

The suspicious death of a US Navy chorister draws NCIS: Sydney into the world of obsessive fans, pop stars, and earworms, as they learn how deadly the music business can be.

The discovery of an exsanguinated sailor takes NCIS: Sydney into the world of modern-day vampires, family feuds, bespoke vodka and a nocturnal matriarch with a penchant for blood.

The team battles searing temperatures to investigate the death of a U.S. Marine corporal killed during a joint training exercise between U.S. and Australian troops.

With a Stinger missile and murderer in the wind, and Darwin's World War II Commemoration ceremony fast approaching, NCIS: Sydney races to prevent a deadly attack.