"Exploring the NCISVerse: 1,000 Episodes and Beyond"

The hit CBS show NCIS is set to air its 1000th episode, celebrating over two decades on air and spawning four spinoffs. In honor of the milestone, a special looking back at the show over the years will air, featuring never-before-seen interviews and clips with the cast. The special will also provide a glimpse into the future with two new shows coming to the franchise, including an origin story for Mark Harmon's character and a series starring fan-favorites Cote de Pablo and Michael Weatherly. ET's NCISVerse: The First 1000 will air on April 8, with the 100th episode of NCIS set to air on April 15.