Charlie and Amita's have an intimate wedding with Larry performing the ceremony. Alan is dead set on moving out of the house now; as he said he would when Charlie got married. Meanwhile, during a scuffle while making an arrest, Don's gun gets knocked out of his hand, and is stolen. The team's sole focus now is on locating the whereabouts of Don's stolen gun. LAPD reports two dead drug dealers in the worst part of town and the slugs from the murder weapon match Don's gun. The team discovers various social network websites referencing "Cop's gun", and a photo of the dead drug dealers. A vigilante gun taking care of what the cops can't is the message spreading around the websites. The gun is covertly being passed around to various vigilantes around town. The trail leads them to a suspect who has been victimized by a terrifying neighbor who the police have been unable to arrest. They find the gun has been picked up by the family's 15 year old son who is hoping to fix the problem. Ultimately Don is able to get the gun back from the teen and Ian Edgerton shows up to arrest the terrorizing neighbor who is a fugitive from Florida Sate Prison. Larry and Alan will be renovating the garage into a guest house for him while Charlie and Amita are in England. Resolved in his decision to stay with the F.B.I., Don asks Robin to marry him, and she says yes.
