A "meter maid" sees a dead body in the living room of a private home in Washington, DC; the victim, a retired Marine colonel, received seven blows of an ax; due to atypical circumstances Gibbs and company question a prime circumstantial suspect who has not confessed; Gibbs and Tony talk with the suspect, Nick, who is the troubled and conflicted 18-year-old son of the victim; Nick adamantly denies any involvement. The mother is absent but not divorced; she dropped out of sight two years ago. The Duckman sees, recognizes, and interprets an important clue, which went unnoticed during the first autopsy (at the Metro PD). Vance loses patience with Nick and then uses an aggressive technique with him until Nick gives an ostensible confession; however, Gibbs says that there's one problem. Gibbs talks with a neighbor, who says that the widow and mother has returned. Nick helps Gibbs, who then arrests the real murderer.