Mark Harmon's Original Gibbs Replacement Returns to NCIS After 6 Years

The following contains spoilers for NCIS: Origins Season 3, Episode 2, “My Own Worst Enemy,” which aired on CBS on Tuesday, October 13, 2026. NCIS has brought Mark Harmon’s original Gibbs replacement back to the franchise as his son, Sean Harmon, returns in NCIS: Origins Season 3, Episode 2.