The Armed Detective Agency receives an anonymous request--and it's asking for Kyouka's help by name. But during her investigation with Atsushi, ex-Guild member Montgomery keeps mysteriously getting in their way! And as another old foe defies death while seeking a triumphant return, a newer enemy--the sinister Dostoyevsky--bares his fangs against both the Armed Detective Agency and the Port Mafia. Threatening to slowly but surely swallow the dark underbelly of Yokohama, how will this devil of a man alter the playing field...?