Takagi Fujimaru may seem like a regular high school student, but behind the cheery facade lies a genius hacker by the name of Falcon. When his father is framed for a murder, Falcon uses his brilliant hacking skills to try and protect his sister and clear his father's name. However, he finds that his father, an agent in an elite government agency, was involved with something far more complex than a simple murder. A terrorist group is plotting against the city of Tokyo and it is up to Falcon, with the help of his friends, to unravel the twisted plans set in place to kill millions of people.
The terrorist leader K has eluded capture, and Fujimaru and THIRD-i have five days to prevent armageddon by neutron bomb, but Falcon is about to find out that his greatest admirer is also his most formidable enemy. This is the day the cult has been waiting for! In this final volume, Bloody Monday arrives at last!