NCIS details the experiences and stories of a team of special agents working for the NCIS. The team, called the Major Case Response Team (MCRT) primarily responds to high-visibility crimes; NCIS is the main federal law enforcement agency of the United States Department of the Navy, investigating criminal activities (e.g. deaths, force protection, treason, etc.) related to the United States Navy and Marine Corps (USMC), and their associated branches of government.