After a cryptocurrency farm is robbed of over $10 million in Bitcoin codes, Sam and Hidoko go undercover, with Sam resuming a likely compromised former alias.

The team helps a former NCIS tech operator search for her missing ex-partner, whom they fear might be working with the gun runners they failed to take down years ago; Deeks reels when his bar gets a negative review.

Sam negotiates and Rountree goes undercover, when a man takes a busload of hostages and threatens to blow it up unless his daughter’s war crimes are posthumously cleared.

NCIS investigates the kidnapping of Master Sergeant Boomer, a military working dog. Also, Sam looks to sell his boat so he can take care of his father who is suffering from Alzheimer's.