A team of special agents, operating outside the military chain of command, must investigate any crime with pieces of evidence connected to Navy and Marine Corps personnel, regardless of rank or position. Character-driven stories with surprising twists play a large role in the second season of NCIS (Naval Criminal Investigative Service). The NCIS team of investigators is led by Special Agent Leroy Jethro Gibbs (Mark Harmon), an experienced investigator with sometimes unorthodox, but always-effective methods. Working under Gibbs are Special Agent Anthony Dinozzo (Michael Weatherly); Special Agent Caitlin Todd (Sasha Alexander); Forensic Specialist Abby Sciuto (Pauley Perrette); and NCIS's medical examiner Dr. Donald "Ducky" Mallard (David McCallum). Additionally, joining the staff this season will be Special Agent Timothy McGee (Sean Murray) whose communication and computer skills outweigh his naiveté. Whether investigating murder or espionage, the NCIS goes global in their quest to solve all crimes with Navy or Marine Corps ties.