All the OG characters who will return for NCIS' 1000th episode

NCIS is entering rarified air. The procedural drama will hit the 1,000 episode mark on Monday, April 15th. We're in a renaissance period for the franchise as a whole, between the launch of an Australian spinoff, plans for additional spinoffs and prequels, and the confirmation that the main show will return for a 22nd season on CBS.

The speculation over what will occur in the 1,000th episode has dominated a lot of the season 21 conversation. So much so, in fact, that Entertainment Tonight put together a special titled NCIS: The First 1,000 to commemorate the event. The special included lots of fun interviews with the cast and crew, but what it didn't include was a rundown of who was going to return for the special episode...

That's where we come in. While some details have kept very close to the chest, and other seems to be wishful thinking at this point, there are a few original characters who will pop up in episode 1,000 in one form or another. Let's break them down.

Tobias Fornell will drive the story

The biggest return in terms of original cast members is Joe Spano, who played Tobias "T.C." Fornell for a whopping 19 seasons. The character dates all the way back to the pilot episode, and typically helped the team the best he could despite the fact that he was an FBI special agent and not an NCIS member. He also was good buddies with Leroy Jethro Gibbs (Mark Harmon), which helped.

The promo for episode 1,000, titled "A Thousand Yards," sees Fornell reach out to Alden Parker (Gary Cole) and the team after he gets targeted by a perpetrator from his past. He will play a pivotal role in tying the events of the episode back to earlier events in the show, and hopefully, he will make it out of the episode alive.

Caitlin Todd will return for a (technical) cameo

The same will not be possible for Caitlin Todd, who has been confirmed to make a cameo in the 1,000th episode. Todd, played by Caitlin Alexander, was a core member of the team during the first two NCIS seasons, but her arc came to a shocking end when she was murdered on the job.

There hasn't been much mention of Todd in recent years, but "A Thousand Yards" will pay tribute to her by including a photograph of her during a crucial scene. So while a cameo in the physical sense, it's as good as far are going to get given that the character has been six feet under for nearly twenty years.

The team confront a mysterious enemy from the past

Technically, the show could pull out all the stops and opt to bring Caitlin Alexander back via flashbacks, but it may serve as a distraction depending on how important the character is to the overall plot. The inclusion of Todd's photograph just have us theorizing that the perpetrator who is targeting Fornell has ties to Todd as well.

The official synopsis for "A Thousand Yards" reads as follows:

"NCIS comes under attack by a mysterious enemy from the past; Vance tries to mend fences with his estranged son by explaining why, despite the ongoing dangers of his job, he still chooses to stay at NCIS."