Season 10, Episode 1: "Extreme Prejudice"
At the beginning of the episode, we saw Ducky being treated by a medical team. While he survived the heart attack, we still weren't sure who survived the bombing. It turned out that Jonathan Cole was the only agent killed in the line of duty. Abby, McGee, Tony, Ziva, and Gibbs all escaped with their lives.
Of course, Dearing was still on the run. He met an undercover FBI agent named Lorraine, who offered to take him home. Once he arrived, he planted a bomb in her bathroom, later sending a text message to taunt her by saying she would die any second. With a bright flash, Lorraine's life, and undercover mission to apprehend Dearing, was finished.
Dearing wasn't put off when NCIS used his sister-in-law, Joanne, as bait to get him out of hiding. He just decided to turn the tables. After placing a bomb inside of his own car, Dearing led NCIS to believe he had committed suicide. However, a lab test revealed that the body only shared 50 percent of Dearing's DNA. Joanne admitted that Dearing paid her to keep silent and that she had reason to believe Dearing may have dug up her deceased husband's body, planting it in the car as a diversion.
Gibbs wasted no time tracking down Dearing, who was hiding in a remote cabin. As Dearing reached for a gun to kill Gibbs, our favorite NCIS leader grabbed the first knife he saw and stabbed the terrorist in the stomach. At long last, the feud was over.