Two years have passed since the final battle with Sephiroth. Though Midgar, city of mako, city of prosperity, has been reduced to ruins, its people slowly but steadily walk the road to reconstruction. However, a mysterious illness called Geostigma torments them. With no cure in sight, it brings death to the afflicted, one after another, robbing the people of their fledgling hope.

A wave of gruesome murders is sweeping Tokyo. The only connection is a bloody X carved into the neck of each of the victims. In each case, the murderer is found near the victim and remembers nothing of the crime. Detective Takabe and psychologist Sakuma are called in to figure out the connection, but their investigation goes nowhere…