A man stumbles out of a park, having been shot and the team discover that he's a Marine who went missing in action during a mission in Afghanistan six years previously. In addition, they also discover that the man has two separate lives and is married to two different women. Meanwhile, Ducky's strange behavior has the team, Abby and Ziva especially concerned.
Also known as Christian Wells. He went MIA from Afghanistan six years previously before re-emerging with a new identity. Was shown to have married two women using both his original and new identity. Tony attempted to question him, only for the efforts to increase Mayne's pressure. It's presumed that this is what led Mayne to suffer a fatal caradic arrest, resulting in his death.