Who is the deadly terrorist known only as Sahar, and where will they strike next? This central mystery runs throughout Season 17 as Special Agent Leroy Jethro Gibbs (Mark Harmon) and second-in-command Senior Special Agent Timothy McGee (Sean Murray) race against time to identify, locate and neutralize Sahar and save countless lives including their own. NCIS takes on some of the most intense cases of their careers along the way, from murdered Marines and attacks at Arlington National Cemetery to crashed fighter jets and secrets that threaten to tear their team apart. Co-stars Wilmer Valderrama, Emily Wickersham, Maria Bello, Brian Dietzen, Diona Reasonover, Rocky Carroll, and David McCallum work together to deliver justice all over the world in this thrilling 5-disc, 20-episode collection.