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.
During a training jump a Marine dies when his main chute fails to open, and he fails to pull his reserve chute. Kate joins the NCIS team, and they investigate; they identify not only the murderer and his method but also a drug connection.
US Navy commander "Seadog" washes up dead on a North Virginia beach. 2 dead, alleged drug dealers are found nearby. All 3 are shot. NCIS, joined by DEA and FBI, investigate.
A swimmer finds the weighted body of a seaman who has disappeared from a destroyer of the US Navy. The NCIS team investigate; they find a petty officer connected with the victim and the death, and they save the skipper from an explosion.
A hunter finds an aircraft cargo pod containing the mummified body of a Naval disbursing officer who disappeared from his aircraft carrier, as did 1.2 million dollars. The NCIS team correct some old mistakes, and now they make things right.
A chef finds a naked sailor inside a freezer at a restaurant in Rota, Spain, during a port visit by USS Enterprise; shortly afterward at sea another sailor freaks out on the flight deck; soon one of them dies. Gibbs and his team solve it.
Workers find the decomposing body of a man, apparently a submariner, inside a drum of acid. The team treats the case as both a murder and a theft of identity. Gibbs and Kate go aboard a sub at sea, find the bad guy, and save the crew.
A naturalized petty officer of Egyptian descent dies in the US from massive bleeding due to an intestinal blockage caused by emeralds; he had just arrived from Camp Delta at Gitmo. Gibbs and others investigate at Gitmo and prevent a murder.
Two Marine majors supposedly die during a classified operation in an undisclosed foreign country; one of them purports to call home. The team investigate; they encounter much interference, but they succeed, and they reach a happy ending.