A salvage team finds Flight 912, a plane that crashed in 1983, with a dead diver inside. Quinn confronts Wes Cullen about the bomb at McGarrett's house. McGarrett and Quinn tail Cullen. The diver was planted on the plane recently. Grover speculates that the killer had been diving with the dead man. McGarrett and Quinn switch to following the man who met with Cullen. Joe Ennis, whose brother was on the plane, said people are continuing to look for answers, that the truth will be covered up. Adam finds a popular conspiracy theory that the Stars Wars defense program caused the crash. The man McGarrett and Quinn are following is Stan Bishop, who picks up four men with black bags. Grover and Tani grab conspiracy theorist Tim Pollack, who denied to have anything to do with the divers. He suggests they check Delphi Son, another conspiracy theorist. The men dig up a barrel full of cash. ISeveral first-class seats were removed from the plane, with something hidden in one of them. McGarrett's truck has a punctured tire. Delphi Son is Joe Ennis. His brother Ron was suspected of a jewelry heist in New York before taking the plane back to Hawaii. Joe is missing and is on his way to meet the killer. Sara Brown is an underwater welder who had worked with the dead diver before. Ennis pulls a gun on Brown but she shoots him first. Tani shoots Brown, who falls in the water. They battle underwater, with Brown pulling a knife. Tani eventually wins and has to perform CPR on Brown. The black box had been wiped. McGarrett invites Quinn to join FIve-0 and she accepts. Then she is arrested by CID. Money was planted in her apartment. McGarrett confronts Cullen, whose house then explodes.