Here's What Really Happened To Gibbs's Mother On NCIS

After 18 seasons, both Leroy Jethro Gibbs' work and personal life have been pretty well-dissected on CBS' NCIS. It's inevitable that on a drama of this type, featuring people whose work involves dangerous situations, personal relationships bleed into the work environment. Heck, the show wouldn't be half as interesting otherwise. And there's been a lot to reveal about Gibbs, from the murder he committed in revenge for the death of his wife and child to his less dangerous personality quirks, such as his aggressive love for his morning coffee. Fans have also been able to learn some things about Gibbs' family, including his relationship with his father, Jackson, and his multiple marriages and romantic relationships (usually with redheads) that haven't worked out.

Even as speculation continues as to whether or not actor Mark Harmon will leave the role of Gibbs behind at the end of this season, Gibbs still remains at the heart of the Naval Criminal Investigative Service, and people remain curious about his past. If you've ever wondered about Gibbs' mom and how she might have influenced Gibbs and his relationships, you may have missed (or forgotten) an episode which explained what happened to her, eight seasons ago.

In "Namesake," the fifth episode of the 10th season, the NCIS team investigates the murder of a Navy officer. At a pawn shop, Gibbs sees a Congressional Medal of Honor and discovers that it belonged to his namesake, Leroy Jethro Moore (Billy Dee Williams). Moore was his father's best friend and an inspiration to the young Gibbs in his military career. Upon further investigation, he learns that Moore needed the money from the sale to fix an electric lift at his group home, where he moved after falling out with Gibbs' father.

Gibbs confronts Jackson (Ralph Waite) about why. Eventually, Jackson tells him the truth in an emotional scene: "He killed your mother, Jethro," he says. Jackson reacts with surprise when Gibbs, who was 14 at the time, says he'd known that his mother actually died of a drug overdose, not of cancer. "Your mother was in pain, Jethro," Jackson said. "She didn't want to fight anymore. She confided in LJ that she was going to overdose. He didn't stop her. And he didn't tell me! She had time left, Jethro, and I wanted every minute of it. He cheated us. We deserved to have that time with her!"

Gibbs talks to Moore again, and Moore tells him that he understood Ann's pain and looked the other way when she decided to die. The two discuss the possibility that the elder Gibbs was angry not just because of Moore's inaction but jealousy that he was the one she told. Moore confesses that he loved Ann, too, and that they maintained a "special relationship until the day that she died." 

In the end, Gibbs and Moore come to Jackson, and Gibbs says, "Time to end the feud," pointing out they all loved the same woman. Later, Jackson goes to Moore's retirement home and returns the Medal of Honor to him, inviting him to come back to Stillwater. Along with settling what exactly happened to Jethro's mom, the episode showcases Gibbs' skill in making peace between his father and his namesake.