A secret investigation by the Special Internal Affairs Investigation Unit was initiated. This was due to an internal whistleblower revealing that there is a mole from the Female Torture Research Institute within the agency. The members, known as 'Ghosts,' are hidden and infiltrate various departments undercover to conduct investigations. Ame Okajima (Ikumi Blackwood), a second-year rookie detective in the Life Crimes Division, was chosen as one of these members. She hides her identity as a 'Ghost' and is assigned to the International Crime Investigation Department as the successor to Masayo Kagurazaka.
