The death of an American seaman on a U.S. nuclear submarine during a ceremony on Sydney Harbour is investigated in a joint effort between America's NCIS agents afloat and the Australian Federal Police.

When a Navy compliance officer is found dead in a waterhole from a snakebite, the team works to uncover the origin of the rare, deadly taipan that is uncommon to the area where the officer was discovered.

When a shark spits out an arm wearing U.S. Navy equipment, the team's investigation tests the loyalty of a band of former Navy divers.

When a U.S. petty officer's body is found in Sydney's historic and haunted Rocks area, a decades-old Navy Cross medal holds the clue to solving the murder, leading the team on a wild chase to catch a killer.

The team races to save one of their own when Doc Roy and his dog are involved in a hostage situation at their local dog cafe.

When a man in a concealed U.S. Navy jacket drops dead from a cocaine overdose on a crowded bus, the investigation pulls Evie back into her past as an undercover narcotics cop.