The official synopsis for the final season is as follows:
This season, the world is finally recovering from the deadly virus that devastated the population, but global political unrest remains. Tom Chandler has retired and his former crew has scattered, many having risen in the ranks within the Navy. Sasha Cooper, Lieutenant Danny Green, SBS WO-N Wolf Taylor and Sergeant Azima Kandie are on a covert mission in Panama. When they are wrongly blamed for an attack on the Panamanian president, the consequences for the United States are dire. The Nathan James must fight to prevent invasion by Latin America — and the next world war.
The Last Ship stars Eric Dane, Adam Baldwin, Charles Parnell, Travis Van Winkle, Marissa Neitling, Christina Elmore, Jocko Sims, Kevin Michael Martin, Bren Foster, Bridget Regan, Jodie Turner-Smith, Emerson Brooks and Fay Masterson.