S.1209. After the threat of the mafia organization Armata was gone, the Republic of Calvard regained its former peace. But one day, in a corner of Edith City, a bizarre incident occurs in which a CID (Central Intelligence Department) special operations squad was found slaughtered. The Calvard Police and Bracer Guild begin investigating the matter. But sensing that a new time of chaos may come, underground factions also start making moves. Meanwhile, Spriggan Van Arkride also begins his investigation, kick-started by a visit from an unexpected someone. Who is the culprit behind the massacre? Why did they do it? And what will happen to Agnès, who is searching for the Eighth Genesis, the last legacy of her great-grandfather? The brutish roar of a crimson beast, and an encounter with a young boy and girl seeking “something” will lead them down a “Trail” that they cannot escape.