The Season 19 Gibbs Clue That Has NCIS Fans Buzzing

Contains spoilers for "NCIS" Season 18 finale

The final episode of "NCIS" Season 18 was an emotional one. Fans had to say goodbye to fan-favorite character Ellie Bishop (Emily Wickersham) as she departed her unit. Of course, audiences have come to expect these emotional goodbyes as many characters have come and gone from the long-running series over the years. However, the one person everyone can count on to show up for some investigative work is Leroy Jethro Gibbs (Mark Harmon). 

The NCIS Supervisory Special Agent has been part of the ensemble cast since the show's first season, and even though he's had his fair share of dust-ups over the years, he always comes back ready to report for duty. Of course, nearly two decades on the same show is a long time, and naturally, rumors have persisted about Harmon's retirement. For a brief period, fans believed Harmon might bite the dust when the Season 18 finale saw Gibbs drive out to sea, only for his boat to explode unexpectedly. Luckily, before the credits rolled, there was an extra scene showing Gibbs returning to shore. 

All this time later, fans have wondered how exactly Gibbs survived the blast. All is set to be revealed in Season 19, and there's now a cryptic message for fans to decipher before the new season airs on September 20. 

Is Gibbs going into the shadows?

While Mark Harmon has signed on to appear in Season 19 of "NCIS," reports indicate it will be in a limited role. TVLine suggests the actor has made a "limited" commitment, so even though Leroy Gibbs will be back in some capacity, it sounds as though other characters will take on more significant roles. This knowledge only adds to the confusion caused by the Season 18 finale. Who caused Gibbs' boat to explode? What's Gibbs up to now? Is he still on the team?

The official "NCIS" Twitter account isn't making anything easier with its latest post, consisting of three rowboats with the tag "#NCIS." It's caused a frenzy on social media as everyone has a theory of what will happen in Season 19. The most common is that Gibbs caused his own boat to explode. It would certainly explain how he knew to get off it just in time, but that still doesn't answer why he would do such a thing. @JonesTanyanika has one of the most plausible theories out of anyone: "I believe the boat blowing up is a setup by Gibbs so can he can work off the grid."

As you might remember from the Season 18 finale, Gibbs and Marcie (Pam Dawber) are hot on the trail of a killer when Gibbs' boat went up in flames. It would make sense if Gibbs believed the only way he could close in on the killer is to make them think he's dead. This allows him to work on the case in the shadows while the rest of the team acquires more information and works on other matters. 

Other theories involve Gibbs getting amnesia and him going on a secret mission with Ellie. Hopefully, more answers come to light on September 20 on CBS.