NCIS: Origins executive producer and narrator Mark Harmon explains why his son, Sean, isn’t returning as Young Gibbs. Set to premiere on CBS in just a matter of days, NCIS: Origins is the first prequel in the history of the NCIS franchise. It follows Leroy Jethro Gibbs in the early 1990s. Although Sean Harmon is involved behind the scenes in the new show, he won’t be appearing on camera. Instead, Bridge of Spies actor Austin Stowell steps into the lead role.
