Gibbs's team is sent to investigate when the body of a sailor is found on board the USNS Chimera, a top-secret naval research ship sailing in the middle of the ocean. After boarding the ship, they find it completely abandoned except for the dead man. Things go from bad to worse when Ducky determines that the dead man died from viral hemorrhagic fever with Ziva suspecting that they're not alone and that someone else is on board although there might be another person on board as well but there's also a secret lurking on the ship as well and it's one that could cost the NCIS team their lives....