After the drama surrounding whether or not "NCIS" Season 19 will happen -- which was confirmed after it was announced that Mark Harmon would be returning -- more questions have surfaced in the aftermath.

The question now is how much longer Gibbs will be available. This is because Harmon's new contract is rumored to include fewer appearances.

Yes, "NCIS" is going through some major changes. We don't even know if this will be its final season, and we're not betting on it appearing on the list of the biggest cancelled TV shows.

CBS has announced that "NCIS" Season 19 will debut on Monday, September 20, 2021 at 9 PM ET. This is consistent with historical precedent, with NCIS series almost always debuting in mid- to late-September (the 2020 debut will be in November).

In announcing the return of NCIS, CBS also confirmed the return of Blue Bloods, S.W.A.T., Bull, and Magnum P.I.

Production on the new season has begun, with series co-star Brian Dietzen stating in an Instagram post dated July 9, 2021, "Work starts next week."

The plot of NCIS Season 19 Episode 1 is not yet known - an official description and trailer are likely months away - but we do know that the script is out.

On July 15, writer/producer Christopher J. Walid shared a photo of the episode 1 script on his Twitter page, writing, "First day of season 19. So grateful to be back on set with the best cast and crew in the business." With the caption.

Of course, the episode titles are hidden:

In big news for CBS, "NCIS" is leaving its Tuesday 8 p.m. time slot and moving to Mondays at 9 p.m. Since "NCIS" has been in that time slot for 18 years, this is a seen as a dramatic change.

Mark Harmon is one of four characters expected to return for "NCIS" Season 19. And Harmon may follow David McCallum (Dr. Donald 'Ducky' Mallard), whose presence was diminished in the previous season.

Timothy McGee (Sean Murray) and Katrina Lowe (Jessica Knight) will also return. Wilmer Valderrama (Nick Torres) is also likely to return for "NCIS" Season 19.

As for new characters: "Deadline" reports that Gary Gaul ("Veep," "The Good Fight," "Office Space") will join the series, and the site claims that his appearance is related to Harmon's reduced episode count Specifically, it says, "Cole is expected to help fill the void left by Harmon's reduced screen presence next season."

The big question about NCIS Season 19 is whether Ellie Bishop (Emily Wickersham) will be back; the Season 18 finale of NCIS made it seem like she would not return, and the show's "The Last of Us" finale was a bit of a letdown.

Most seasons of NCIS had a full 24-episode order, but seasons 17 and 18 were shortened due to the Covid-19 pandemic (20 and 11 episodes, respectively).

Since production has not yet begun on this season and it is still too early for NCIS Season 19 news, it is impossible to say whether the show will run at full capacity.

As explained below, NCIS Season 19 depended on whether Mark Harmon wanted to return. The actor reportedly wanted out of the series, and the season 18 finale of NCIS gave the series an opportunity to reduce his role going forward.

So if Gibbs' role is reduced in season 19, it would be a sign that Harmon is done with the show and not to bet on "NCIS" season 20.

The big buzz about Mark Harmon's return to the "NCIS" series began in February when The Hollywood Reporter published an article revealing that Harmon was considering dropping the role of Leroy Jethro Gibbs.

The magazine later reported that "NCIS" would likely be cancelled altogether if Harmon retired. This brought the actor back to the table. However, it now appears that he will only appear in a reduced number of episodes.

NCIS Season 18 ended with Gibbs saying goodbye to Eleanor Bishop and plummeting into the water after his boat blew up. If Gibbs is currently in hiding (to make the serial killer he is pursuing think Gibbs is really dead), we may see less of Mark Harmon this season.