The team was sent to investigate the murder of a building manager who had triggered a bomb in Navy Lieutenant Terence Keith's apartment, the latter of whom had gone missing.  Meanwhile, McGee lost his NCIS credentials and, acting upon advice from Tony, didn't tell Gibbs while trying to find them.  Special Agent Vera Strickland - Mike Frank's last partner - showed up at NCIS to spend the last few weeks of her employment there prior to retirement.  Once McGee notified Gibbs about his missing badge and I.D., he was confined to the building, and Strickland was sent out with Tony to investigate the whereabouts of the missing Lieutenant. They found the guy who sold the C4 for the bomb, and he tries to escape, almost running over Strickland.  Tony tackled her to get her out of the way of the fleeing truck, then shot out the tires and captured the suspect, who eventually told them that he didn't just sell the few ounces necessary for the room bomb, but 200 pounds of C4.  After determining that Lt. Keith was determined to kill his flight school classmates who were aboard a Navy ship, the team tracked him down via Twitter feeds, and Gibbs convinced him not to attempt to bomb the ship.  Lt. Keith turned his plane around and released a dead man's switch, thereby blowing him and his plane up, with no harm to anyone else.