Mark Harmon played special agent Leroy Jethro Gibbs for 18 full seasons on the long-running police procedural show NCIS before finally being written off in the fourth episode of Season 19. But he hasn’t been able to detach from the franchise completely. Harmon returned as Gibbs in the series premiere of the spin-off show NCIS: Origins, and has narrated every episode after that. He also appeared in a special Veterans Day crossover episode between Origins and the original NCIS show, in addition to serving as an executive producer on Origins.

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