In a futuristic Japan, the Sibyl System is charged with keeping the peace. When the state of SEAUn brings the Sibyl System in to test its effectiveness, it becomes a haven of peace and safety—for a time. Eventually, terrorists from SEAUn begin appearing in Japan, somehow slipping through the System's security and attacking from within. Desperate for answers, Inspector Akane Tsunemori is sent overseas to bring the terrorists to justice. But when her investigation forces her into a standoff with an old ally, will she be able to pull the trigger?

While attending a meeting as a Chief Inspector of the Public Security Bureau, Akane Tsunemori received a report that an incident had occurred on a foreign vessel , and this was the beginning of a big and unexpected case.