Sub Rosa

NCIS Norfolk Case Agent Timothy McGee works on a case of a partially dissolved corpse found in a barrel of acid at the Norfolk Naval Base, and calls in the Major Case Response Team to help him. As the investigation continues, it soon becomes apparent that the killer took steps to prevent the body from being identified. Gibbs quickly comes to believe that the motive for the brutal murder was identity theft and his suspicions are further confirmed when it's revealed that although a submariner is dead, no-one has been reported missing, leading Gibbs to believe that an imposter is on one of the submarines. Tony, Abby, and McGee are tasked with identifying the deceased, while Gibbs and Kate are sent underwater on a submarine to vet five possible suspects, one of whom might have been responsible for the murder and to also prevent a possible chemical attack from taking place.