NCIS investigates the apparent suicide of a retired Navy officer who was in Palmer and Knight's grief group; Torres gets a call from NCIS Special Agent Jane Tennant to come to Hawai'i.

The crossover continues on NCIS: Hawai'i S01E18 T'N'T (II).

Special Agent Alden Parker is still on the run with his ex-wife Vivian, so the team investigates who from his past might have a personal vendetta against him in hopes of clearing Parker's name.

The crossover continues on NCIS: Hawai'i S02E01 Prisoners' Dilemma (II).

NCIS agents from Washington, D.C., Los Angeles and Hawai’i, all in D.C. to attend the retirement party of a beloved Federal Law Enforcement Training Center (FLETC) professor, find themselves jointly investigating his shocking suicide.

The crossover continues on NCIS: Hawai'i S02E10 Deep Fake (II) and NCIS: Los Angeles S14E10 A Long Time Coming (III).

NCIS comes under attack by a mysterious enemy from the past. Also, Vance tries to mend fences with his estranged son by explaining why, despite the ongoing dangers of his job, he still chooses to stay at NCIS.