2112; the summer before Akane Tsunemori was assigned to Criminal Investigation Department. Teppei Sugo, an accomplished pilot of the Defense Army, joins the military operation in Okinawa. Three months later, an unmanned combat drone opens fire on the Ministry of Defense in Tokyo. Enforcer Tomomi Masaoka is dispatched to Sugo's military base to investigate the truth behind this case.

Acreditando na humanidade e na ordem, a polícia Akane obedece ao sistema informático Sibyl. Mas quando se depara com um mestre do crime que pode iludir este sistema "perfeito", ela questiona tanto Sibyl quanto ela mesma.