A man, while impersonating Tony, checks into a hotel, dumps down a trash chute a bag containing a body, then checks out; predictably, Gibbs and company investigate. Fortunately, Tony has a good alibi for the night in question. The victim was a Navy lieutenant; Ducky describes evidence of both strangulation and a knife wound to the heart. The impostor approaches Tony; he is the first person convicted as a result of Tony's investigative work after Gibbs went to Mexico on hiatus; the victim was the prosecution witness in that case; the impostor has recently become released from prison. The impostor also has an alternate explanation, and he asks Tony to consider certain evidence. Gibbs places Tony back in charge of his case, and Gibbs says that the impostor was innocent of the previous charge. After pursuing many clues, the team put together most of the pieces but not all of them.