在悉尼港举行的AUKUS仪式上，一名美国船员在一艘美国核潜艇上死亡，这是美国NCIS海上特工和澳大利亚联邦警察联合调查的结果。

当一名海军合规官员被发现死于水坑中的毒蛇咬伤时，该团队正在努力揭开这种罕见的致命大班的起源，这种大班在该官员被发现的地区并不常见。

当一条鲨鱼吐出一只穿着美国海军装备的手臂时，该团队的调查测试了一群前海军潜水员的忠诚度。

当一名美国士官的尸体在悉尼历史悠久、闹鬼的岩石区被发现时，一枚有几十年历史的海军十字勋章为侦破这起谋杀案提供了线索，带领团队展开了一场疯狂的幽灵追逐，以抓捕一名杀手。

当Doc Roy和他的狗在当地的狗咖啡馆遭遇人质事件时，该队正竞相拯救自己的一只狗。

当缉毒队一位老同事的可疑死亡将Evie拉回一场秘密卧底行动时，DeShawn在对朋友的忠诚和对团队的忠诚之间左右为难。

A glitzy tech launch turns into a disaster, leaving half of NCIS: Sydney trapped underground, and the others scrambling to save the day before the clock and the oxygen runs out.

When JD's son is kidnapped by an international assassin in exchange for a wanted criminal in NCIS custody, the team frantically tries to get his son back safely without trading in a criminal.

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.

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.