Special Agent Leroy Jethro Gibbs is the leader of a team of special agents belonging to the NCIS (Naval Criminal Investigative Service) Major Case Response Team. Gibbs, a former Marine, is a tough investigator and a highly skilled interrogator who relies on his gut instinct as much as evidence. Gibbs' second in command is Senior Field Agent Tony DiNozzo, a womanizing, movie-quoting former Baltimore Homicide Detective, who despite being the class clown always gets the job done. The team also consists of probationary field agent Ziva David, a former Mossad officer who is a skilled fighter, as well as Junior Field Agent Timothy McGee, a computer-savvy agent often mocked by DiNozzo. Assisting them are Abby Sciuto, the energetic-but-Goth lab tech who is like a daughter to Gibbs, and Dr. Donald Mallard, nicknamed Ducky, the eccentric medical examiner full of unusual stories. This team of elite agents, based in Washington, D.C., solve criminal cases involving Marine and Navy personnel and their families, sometimes traveling the United States - or the world - to do it.