The serious wound received by Slur caused him to switch with the personality of Rion Akao! Faced with this perfect imitation of their old friend, Sakamoto and Nagumo do not lead wide. However, the priority for all three is to escape the FJA agents who pursue them. It is then that a dreadful old man appears before them... With the return of the most terrifying assassin of the FJA, the arch of the Exposition: the assassins of the century has reached its climax!