‘NCIS’ 20th Anniversary: 11 Most Shocking Moments (So Far)

Mark Harmon, Sasha Alexander, and Cote de Pablo in 'NCIS'
CBS

It was 20 years ago, on September 23, 2003, that NCIS (previously titled NCIS: Naval Criminal Investigative Service) premiered after a two-episode backdoor pilot on JAG the previous spring. Here we are, and the CBS hit is showing no signs of slowing down: It’s going into its 21st season and has three multi-season spinoffs (with an international version coming later this fall).

NCIS has changed quite a bit over the years, with none of its original stars from that first episode still a series regular (David McCallum now recurs). But what’s led to the complete overhaul — though Sean Murray did join in Season 1 and continues to star — only makes up a few of the most shocking moments from the procedural drama over 20 seasons so far.

So grab your gear (or, you know, snacks) and scroll down to check out some standouts (and which episodes to watch for each).

NCIS, Seasons 1-20, Streaming Now, Paramount+

Michael Weatherly in 'NCIS'
CBS

Tony nearly dies of the plague ("SWAK," Season 2, Episode 22)

Tony (Michael Weatherly) makes the mistake of opening an envelope that’s sealed with a kiss and inhaling the white powder inside … which contains genetically-altered pneumonic plague. He’s the only one who tested positive — though Kate (Sasha Alexander) stays with him in quarantine at the hospital — and while it was rendered impervious to antimicrobials and he progressively gets sicker, he’s healthy enough to survive. (Tony’s brush with the plague comes up later in the series, including when the team worries a burned body could be his — but that man never had the plague! — and when NCIS: New Orleans needs an expert for a case.)

Sasha Alexander in 'NCIS'
CBS

Kate is killed ("Twilight," Season 2 Finale)

With Gibbs’ (Mark Harmon) life in danger, Kate is in charge of his protection detail and takes a bullet — in the vest — while doing so. Just as they think the threat was over, however, tragic strikes. “Protection detail’s over, Kate,” Gibbs informs her as he and Tony help her stand. “You did good,” Tony remarks. “For once, DiNozzo’s right,” Gibbs agrees. “Wow, I thought I’d die before I ever heard —” Kate begins before she’s shot in the head and killed, from another rooftop, by terrorist Ari Haswari (Rudolf Martin). “Sorry, Caitlin,” he says.

Cote de Pablo in 'NCIS'
CBS

Ziva kills Ari ("Kill Ari: Part 2," Season 3 Episode 2)

During the search for Ari in the wake of Kate’s death, the terrorist’s half-sister, Mossad officer (and future team member) Ziva David (Cote de Pablo), comes to the United States to stop them from killing him. Though she initially refuses to believe that he’s gone rogue, she comes to accept what happened, and it’s Ziva who kills Ari before he can shoot Gibbs.

Mark Harmon in 'NCIS'
CBS

Gibbs killed his family's murderer ("Hiatus: Part 1" & "Hiatus: Part 2," Season 3 Episodes 23 & 24)

Over the years, more and more people come to learn the truth of Gibbs’ past. But that all begins during this two-parter, as a result of Gibbs waking from a coma following an explosion with memory loss. While he was fighting in Desert Storm, his first wife witnessed the shooting of a Marine and identified the killer as Mexican drug dealer Pedro Hernandez. She and their daughter were then killed. And Gibbs, upon learning what happened, took matters into his own hands.

Lauren Holly in 'NCIS'
CBS

Jenny is killed ("Judgement Day," Season 5 Episode 18)

Just as we’re wondering if it would be her health that would take Jenny (Lauren Holly) from the director’s chair at NCIS or her life, it’s instead a failed mission from her past that leads to her death, during a shootout in an abandoned diner in the desert, with Mike Franks (Muse Watson) by her side.

Liza Lapira in 'NCIS'
CBS

Michelle Lee is the mole ("Cloak" & "Dagger," Season 6 Episodes 8 & 9)

At first, Michelle (Liza Lapira) is just a lawyer and agent who briefly works on Gibbs’ team while the others are sent on other assignments, as well as a love interest for Palmer (Brian Dietzen). Then comes the reveal that there’s a mole at the agency, and no, it’s not the agent (Jonathan LaPaglia’s Langer) Michelle frames. She’s trying to protect her family, she eventually reveals, ultimately sacrificing herself when the person behind it all uses her as a shield.

David McCallum in 'NCIS'
CBS

Ducky's heart attack ("Till Death Do Us Part," Season 9 Finale)

The danger hits very close to home, with a bomb going off at the Navy Yard, where almost the entire team is. Meanwhile, elsewhere for Palmer’s wedding day, Ducky (McCallum) receives word of what’s happened (“How many?”) … and has a heart attack!

Michael Weatherly in 'NCIS'
CBS

Ziva's dead ... and had Tony's daughter ("Family First," Season 13 Finale)

News of a terrorist attack shakes up the team, especially Tony, with reports of Ziva’s death. It’s then that he learns that the only survivor of the fire is their daughter (!) Ziva never told him about. Tony then leaves NCIS.

Cote de Pablo in 'NCIS'
CBS

Ziva's alive ("Daughters," Season 16 Finale)

Three years after her “death,” the CBS drama reveals that Ziva’s actually alive, following a strong suggestion that she could be. She shows up in Gibbs’ basement — at a time he’s seeing dead people — and gets right to business: “Hello, Gibbs. No time for pleasantries. You’re in danger.” He stares at her, so she asks, “Aren’t you going to say something?” At that point, all he can say is her name.

Sean Murray in 'NCIS'
CBS

Gibbs shoots McGee ("Head of the Snake," Season 18 Episode 5)

After Season 18 opens up with Gibbs shooting McGee (Murray), it’s the fifth episode that reveals that yes, it really does happen and for a good reason. McGee’s approaching a plane wired with explosives, and his comms are out, so it’s the only way — when warning shots don’t work — for Gibbs to stop him.

Mark Harmon in 'NCIS'
CBS

Gibbs leaves ("Great Wide Open," Season 19 Episode 4)

If you’d told us that Harmon and his character, Leroy Jethro Gibbs, wouldn’t be part of the show for every one of its episodes until its (eventual) finale, we wouldn’t have believed you. Yet, that’s what happens in Season 19, following Gibbs being suspended, with him ultimately deciding to stay in Alaska after (unofficially) wrapping up a case. The drama is heading into its second full season without him.