Leroy Davis, a hitman who has dementia, comes to McGarrett to confess to 18 murders, handing over his collection of weapons. FBI Agent Colin McNeal pulls his gun on Adam, forcing him into a car. Leroy leads McGarrett to one of his burial sites, where there are seven bodies. McNeal takes Adam to meet his half-sister, Noriko, who is the new power behind organized crime. She kills McNeal. She tells Adam her story. Noriko says her DNA was planted on Hideki's body, probably by McNeal. She wants Adam to get Shioma's $20 million so she can disappear. Noriko has men watching Kono and Chin Ho, and she threatens to kill them. McGarrett recognizes Leroy's house because his father Jack frequently drove by it. Adam has known where the money was all along, and Jessie insists on going with him to get it. Among the remains found is Det. Jake Ozuki. He almost killed Jack McGarrett, but Steve's birth caused his father to break off his investigation. Grover and Junior arrest Gary Kahele, Leroy's former boss who ordered the murders. Adam and Jessie visit Mr. Kimura, to withdraw all his money, from the Yakuza's unofficial bank. Now that Adam is withdrawing the money, his father's debts won't get paid, which will cause trouble for Adam. Leroy takes McGarrett to another burial site. Leroy said he became a hitman because, as a Vietnam vet, he used the only skill he had. Jessie takes off with Adam's car and money. Adam calls Tani to get help. McGarrett arrests Leroy, who admitted he confessed because of the dead cop's son. All the victims' relatives waited to thank McGarrett for giving them closure. Adam and Tani catch up with Jessie, only to find her shot dead and the money gone.