Humanity shares the world with vampires. Centuries ago, Armageddon cast a darkness across the world. From that darkness, vampires emerged. Now there are two races, humans and vampires, trembling on the brink of war. Abel Nightroad is a Vatican priest and agent of AX, as special operations group that protects the fragile equilibrium between the two races. Neither human nor vampire, he uses his unique abilities to seek a safe path for all.