If Mark Harmon's Gibbs ever does return to NCIS, here's how it might happen. Harmon has been a member of the NCIS family ever since it emerged as a JAG spinoff in 2003

NCIS season 19 Gibbs left the team to stay behind in Alaska, having achieved the kind of peace he had long been searching for after his wife and daughter's deaths.

Since his departure, NCIS has referenced Gibbs several times, but the show hasn't given much of an indication of his return.

While NCIS has shifted its focus to welcome the team's newest leader, Alden Parker (Gary Cole), to the action, it is clear that Gibbs looms large both for the characters and the fans of the CBS show.

NCIS has been renewed for at least one more season, so the upcoming season 19 finale will not be its final episode.

Incidentally, the finale will put a main character - Parker - in a very difficult situation when he's framed for murder.

This would be the kind of plot premise that could pull Gibbs back in. Not to mention that a season finale would be a good place for a surprise return.

In other words, there are plenty of opportunities ahead for a potential reappearance, provided Harmon is interested in breaking Gibbs' current happy ending.