A helo ferries the Gibbs team to a Naval research vessel at sea to investigate the death of a lieutenant commander, who was a PhD and a marine biologist; initially the gang encounters no human being; later they find the body of the victim inside the freezer in the galley; the crew and the lifeboats have disappeared. Ducky says that the death resulted from a viral hemorrhagic fever, and that they all have become exposed and may die before the next day. Abby helps Tony with some lab work. Eventually the cook appears, the communication officer does likewise, and visitors arrive. The gang figure it out, so they borrow a boat, and then the ship disappears.