At 04:19 in northern Virginia an 18-wheel truck accidentally and fatally hits a Naval Reserve lieutenant who had swerved and woven on a freeway, parked on the left side, and walked toward an emergency call box on the right side; Gibbs and company investigate. Ducky sees telling evidence at the site, finds an explanation in his workshop, and offers a theory. The gang check out the obvious leads; Ducky meets and courts an attractive and interesting new ladyfriend. While hiking through a state park, the team find a dead SUV and a dead body under circumstances similar to those of the other victim; this vic is a civilian, but his estranged wife is a Marine on active duty in Afghanistan. When Duckman again sees his new honey, he gets two real surprises. Meanwhile, Gibbs and the gang figure out what's happened, so they head out to help; they wrap up some loose ends; Gibbs offers Duck a ride home.

An explosion and a fire damage an offshore drilling platform near the Virginia Capes, killing one (a major in the US Marine Corps Reserve) and injuring many others; Gibbs and company, along with Abby of the CGIS, investigate. The CEO and the chief legal counsel of the oil company assure the SecNav and Gibbs of their utmost cooperation. Tony and McGeek trace one lead, which appears to reach a dead end, but which leaves egg on McGoo's face; Gibbs and the other Abby suspect that the target was not the platform but rather the dead victim. Tony and McGee plus Gibbs and Borin revisit the dead end, where they make a major discovery; Abby puts things together in her shop; Borin questions the corporate lawyer in Gibbs's chat room and brings the investigation to a close. Meanwhile Halloween pranks abound, eventually tripping even Tony.