An experimental naval aircraft crashes on Oahu, and Tennant and her team must find who is behind it before classified state secrets are exposed.

Tennant and NCIS must take down a notorious team of international thieves before they complete their final big job and disappear; Kai searches for a new place to live; Lucy and Whistler have a standoff about their previous encounter.

Kai goes under cover with one of Hawaii's oldest surf gangs when a petty officer is murdered.

When a beloved Hawaiian cowboy is shot while out riding his horse, Jane and her team must gain the trust of the Paniolo community to help find the culprits and protect the cowboy's life; Kai tries to convince his stubborn father to see a doctor.

When a Japanese sailor is killed on American soil, evidence links the case to the previous murder of the victim's girlfriend back in Japan; Capt. Milius makes a personal request to Tennant.

When Tennant and NCIS are tasked with finding a kidnapped social media star, they find that she is not who her husband, or her followers, think she is; the team is at odds with Whistler, who has an agenda of her own.