If NCIS‘ Leroy Jethro Gibbs is resurfacing for any sort of sendoff for Dr. Donald “Ducky” Mallard — played by late cast member David McCallum — no one has notified series vet Mark Harmon. Harmon remains an executive producer on CBS‘ NCIS, which kicks off Season 21 on Feb. 12, 2024, but he has not appeared on-camera […]