NCIS: Why Did Mark Harmon's Gibbs Burn Rule 10?

Leroy Jethro Gibbs' list of rules is an integral part of his character. His late wife gave him the idea to form rules to abide by, but sometimes, they do more harm than good. That was the case with one of Gibbs' Top 10 rules: "Never get personally involved in a case." Rule No. 10 came to light on Season 7, Episode 21 — "Obsession." Anthony DiNozzo (Michael Weatherly) confesses to falling in love with a woman who tragically dies on a case. DiNozzo breaks the rule, and comforting him, Gibbs says he struggles with abiding by it, too. 

The rule also comes into play on Season 16, Episode 13 — "She." Gibbs threatens to take Ellie Bishop (Emily Wickersham) off a case after she gets too emotionally invested upon uncovering some of Ziva David's (Cote de Pablo) notebooks about a case from which everyone else moved on. She wants to pick up where Ziva left off, with the episode focusing on how Ellie believes she exists in Ziva's shadow. Ellie makes the case they can learn much from Ziva's notebooks, and Gibbs comes around to understanding her point of view. Ziva was invested in the case, with Ellie taking up the cause, and seeing how much it means to them makes Gibbs reconsider his rule. As a result, he eventually burns it. 

Why did Gibbs burn Rule 10? It seems like a drastic step, but it's an integral component of his emotional journey. The idea of not getting emotionally invested in a case sounds like a good one on the surface. However, finding those notebooks clearly awakens something in Gibbs. It shows Gibbs' feelings toward Ziva and how emotions can be a strength in keeping those we love close to us, even when they're not there physically.

The rule would factor late that year with Season 16's "Hail & Farewell." NCIS investigates the death of Gibbs' fiancée, Major Ellen Wallace (Erin Cummings). Naturally, Gibbs couldn't help but get his emotions involved, and he was actually kicked off the case. But it's healthy for Gibbs to experience these emotions, with his burning of the rule a turning point for his character.

Executive producer Steven D. Binder even commented on the burning to TV Line, "He's had his best friend's daughter in a life-or-death situation, and now he's got Ziva reappearing in his life. We're going to see a bit more of what happens when a guy like Gibbs decides to start doing things because his emotions are taking him there." Burning a rule is also significant because of what it says about Gibbs' relationship with his deceased wife. She inspired the rules, so Gibbs eliminating one illustrates he's willing to let a part of her go. It's not about forgetting her completely, but it's showing how it's okay for Gibbs to display emotions in his work and interpersonal relationships with his colleagues. 

Gibbs burning Rule No. 10 shows growth. He won't be beholden to the rules (and symbolically, the past) as much going forward, allowing him to be more in touch with his emotions and process his feelings in a healthier manner.