Jerry's conspiracy theorist friend Susie is killed while researching the local connection to the Kennedy assassination. Susie was about to prove her theory that Kennedy's cabinet was behind the assassination, and Jerry thinks that's why she was killed. Jerry explained that many of the cabinet members were in Oahu meeting behind closed doors in the days before the assassination, and that they felt JFK was too soft on Communism. Jerry and Chin talked to the men that Susie had interviewed the day before she died. Max determined that the bullet that killed Susie came from a U.S. military sniper's rifle. The FBI seizes evidence in the case from the crime lab. Jerry, Chin and Eric use a lip-reading program to review film taken of the cabinet  members during the 1963 visit, which implicates the advisors. Chin and Jerry are being followed, but the man escapes, leaving a matchbook with a meeting time. They meet the man, Drake, who was an FBI asset in 1963. He told about a meeting by the advisors at a local nightclub he managed, and having a singer plant a recorder at their table. Chin and Jerry acquire the recorder from an estate seller. McGarrett and Danny catch Agent Ward at the impound lot, find out he was spying on Jerry and Susie when she died and arrest him. Jerry plays the tape and finds out the cabinet was talking about a plan to remove Castro from power. Ward admitted he was following Susie after she revealed information about a corrupt chemical.company, and the shooter was hired by company officials.