Mark Harmon is reprising his role as the original Special Agent Leroy Jethro Gibbs in the Nov. 11 episode of 'NCIS: Origins.' The series is a prequel of the original 'NCIS,' in which Harmon played the lead for 18 seasons.
https://people.com/mark-harmon-to-guest-star-on-ncis-origins-4-years-af…