Aboard Air Force One a Naval officer dies after eating with the Potus, then a Marine officer (connected with AF1) also dies in Georgetown in the same way. Abby identifies the cause, and Gibbs thwarts an attempt to assassinate the PotUS.

A young lady emerges from a shallow makeshift grave in Rock Creek Park, Washington, DC; although amnesic she says that there's no time, that there's a bomb aboard a Naval vessel, and that people will die. A passing driver aids her and calls 911; the Metro PD responds, then calls the NCIS. Gibbs and his team investigate. Kate befriends the victim and takes her into her pad, and she slowly recovers a few memories. Gibbs finds a key, then Abby figures it out, then Gibbs and Tony find a body. The ship in question proves to be ashore and inside a building. The team learn the name of the victim, then she begins to recover more memories than she reveals. Eventually she confronts the person responsible for her treatment, and she drops a surprise on him.