The Darkest Thing Gibbs Ever Did On NCIS

Listen, we know Leroy Jethro Gibbs (Mark Harmon) of NCIS lives by an extensive list of rules, but that doesn't mean he plays by them all the time. The NCIS Team Commander is a man with a mysterious past that his co-workers and fans have learned about slowly over the course of the series' nearly two-decade run. And the further down the Gibbs rabbit hole we've gone, the more we've found out about how troubled his history really is.

While there are a lot of incidents both onscreen and off that are pretty grim, one does stand out from the rest. Choosing the darkest action Gibbs has ever taken seems like a tough task at first glance. The former Marine Corps sniper and long time law enforcement officer has found himself in more insane situations during any one season of NCIS than most people do in their entire lives. However, there is one moment from Gibbs' past that clearly haunts him immensely.

While fans of the show will have their own feelings on the darkest thing they've ever seen Gibbs do, for us, one storyline in particular takes the cake.

Longtime viewers of NCIS may take Gibbs' gruff and cold personality for granted, but there is a reason he is the way he is. Before the beginning of the series, Gibbs had a wife, Shannon (Darby Stanchfield), and daughter, Kelly (Mary Mouser). Both were murdered by a cartel member named Pedro Hernandez (Thomas Rosales Jr.) who Shannon was getting ready to testify against. Their deaths had a profound effect on Gibbs, which Harmon himself spoke to in an interview with TV Guide, saying, "His memory of great loss is not something the writers or I or anybody ever expects him to get over. It's too deep."

It took a long time for the rest of the NCIS team to learn this sad fact about Gibbs, and even longer for them to find out the other awful truth of the situation. After the murder, Gibbs tracked down Hernandez and killed him in retribution. While it's hard to not feel sympathetic to this desire for revenge, Gibbs is a career military and law enforcement veteran, and an extrajudicial execution is a serious offense. Someone with Gibbs' experience should know that taking justice into your own hands is a slippery slope that can take one down a bad path.

It's likely that Gibbs does know that, and that it's the reason he kept his involvement in Hernadez's murder a secret for so long.

One of the clearest indications that Gibbs murdering Hernandez is the darkest moment in his life is that it took him decades to tell any of his NCIS colleagues about the incident. Heck, even fans had to wait three seasons to find out. The existence of Shannon and Kelly wasn't revealed until the beginning of season 3, and it wasn't until the two-part season finale that viewers learned about Hernandez's fate.

It isn't until the final episodes of season 7 that Abby (Pauley Perrette) accidentally uncovers Gibbs' secret. The discovery is a major shock to her, to the point where she is paralyzed by indecision regarding whether to expose Gibbs or help him keep his secret. Ultimately, Abby does write up a report about Gibbs' role in Hernadez's death, which leads to several other NCIS higher-ups finding out.

However, even once the secret is out, it remains on a need-to-know basis. In fact, it wasn't until the season 16 episode "...and Executioner" that some of the later additions to the NCIS squad, like Nick Torres (Wilmer Valderrama) and Ellie Bishop (Emily Wickersham), find out. All the secrecy is a clear indication that Gibbs is aware of just how dark he got when he decided to get revenge on Hernandez.

While the news of Gibbs' revenge killing may have come as a total shock to most viewers, in retrospect, it isn't actually that surprising that Gibbs has some serious darkness in his past. The list of tragedies he's endured may not be short, but we're going to go out on a limb and say the murder of your wife and child is likely near the top of the heap for anyone.

From the initial NCIS backdoor pilot that was part of JAG, fans have known Gibbs as a quiet man who is more than a little frigid to those around him. One of the hallmarks of Gibbs' personality is his reluctance to get too close to people. We see this in many of his relationships with his fellow NCIS agents, some of whom he has worked with for years. Although he is not completely closed off to people like Abby and McGee (Sean Murray), it takes him a long time before he's able to open up to them on subjects other than work. Even though we know he had a series of ex-wives after Shannon, we also rarely see him engage romantically, and when there are sparks, such as with Dr. Jack Sloane (Maria Bello), he still seems reluctant to act on them.

Fans have always known Gibbs as the steely quiet type, which is not exactly a surprising trait for someone who lost their wife and daughter so tragically and has lived their life carrying a huge secret. Watching him continue to deal with the darkness in his past is just one of the many things that makes NCIS so engaging after so many years.