In Navy family housing in Norfolk, Virginia, a mother finds a revolver among the personal stuff of her 12-year-old son, Noah; base authorities send the piece to the NCIS; Abby learns that the handgun was recently fired, and that the barrel bears human brain tissue; Gibbs and company investigate. Gibbs, Tony, McGee, and Ziva check the house and talk with Noah and two friends; the conversations lead to a search for a body; Tony, McGee, the boys, and their mothers find the right spot, and McGee finds maggots, a remnant of an ear, and tire tracks; not far away Tony spots the body of a local bully. Meanwhile Abby learns that the gun has been used in three crimes; the gang trace its history; later Abby says that there's another victim. Gibbs recognizes a familiar face; Tony and Ziva find the last body; Gibbs and McGee learn the details about both recent deaths.
—DocRushing