is worried she too is infected with whatever killed the Commander, but she explains it is the same flu that Major Kerry had, revealing that she is in a relationship with him which is against fraternization rules. Following the plane to Washington, Senior FBI agent T. C. Fornell makes a deal with Agent Todd's superior Secret Service Agent William Bear to take control of the investigation and cut out NCIS by ordering Agent Todd to deliver Commander Trapp's body upon landing, as whoever has the body controls the investigation. Despite her protests, Agent Todd follows orders but Gibbs, having suspected such an eventuality, arranged for DiNozzo to impersonate the body allowing their escape. NCIS Director Thomas Morrow later makes a deal with his counterparts for a three-way investigation with NCIS in the lead (as they possess the body). Back at the NCIS headquarters, Ducky is autopsying the body of Commander Trapp, only to find he suffered a cerebral embolism, which is considered a natural cause of death. Gibbs wants the team to keep looking while he joins Agent Todd aboard Air Force One. On board, Gibbs begins to irritate Agent Todd by comparing the plane to the 1997 film Air Force One, whilst discovering that she met Major Timothy Kerry for a drink during her brief stay in DC. Later, another senior officer revealed to be Marine Major Timothy Kerry, is found dead in his car in Georgetown with similar symptoms to those of Commander Trapp. NCIS Forensic Specialist Abby Sciuto is able to find DMSO and snake venom from an Australian Taipan on both Commander Trapp and Major Kerry's uniforms, which could explain why they died. DiNozzo investigates both of them, finding out that Trapp and Kerry used the same dry cleaner and informs Gibbs. Aboard Air Force One, after determining that the current "football" carrier isn't in danger, Gibbs begins an interrogation of Agent Todd as she was the last person with both dead men. Gibbs questions her motive for Commander Trapp's death before revealing Major Kerry was dead as well, and Todd's reaction makes Gibbs believe that she is innocent. NCIS determines that it is a complex terrorist attempt to assassinate the President, and Gibbs realises that goal of Commander Trapp's death was to switch to the backup plane. Todd explains the differences between the backup plane and the main plane, and Gibbs focuses on the armory,