NCIS Special Agent Jethro Gibbs leads his team to investigate all crimes dealing with the U.S. Navy or U.S. Marine Corps. The team continues to deal with a death of one of it's own while being broken up by the new director; they find a mole within their ranks; murder at a Marine base; a home invasion right before Christmas; McGee becomes a hostage at a womens' prison; and Abby is recruited to help out when a government scientist goes missing.