'NCIS' Boss Explains Why Mark Harmon Didn't Return for Ducky's Funeral, Reveals If He'll Ever Come Back

Here's How 'NCIS' Wrote Off David McCallum's Ducky, Plus a Gibbs Update & See Which Cast Member Made a Surprise Return

Here's Why Mark Harmon Didn't Appear in NCIS' David McCallum Tribute Episode

David McCallum's NCIS curtain call: Late actor's character Ducky will 'solve one last crime with the team' as writers pay tribute following his death at 90