Mark Harmon Returning To ‘NCIS: Origins’ As Gibbs For Season 3

Mark Harmon is returning to NCIS: Origins for a season-long arc. Harmon, who previously starred as Leroy Jethro Gibbs for 18 seasons on NCIS, will appear in all episodes of Season 3 as part of a present-day mystery tied to his ‘90s Camp Pendleton days.