In the distant future, Armageddon has triggered the emergence of a second "Vampire's" moon. This ignites a war between humans and "Methuselah," vampires that feed on human blood. Esther Blanchett is an orphan raised in the Church of St. Matthias in the city of Istvan. One day, she meets Abel Nightroad, a priest dispatched to neutralize threats to the Vatican, an organization allied with humanity. Beneath Abel's meek exterior lies his true identity as "The Crusnik": a vampire who preys on his own kind and serves as the Vatican's most powerful weapon. Esther's peaceful life is abruptly ended when the church is bombed and she is betrayed by her sole friend, Dietrich. With nowhere else to turn, she joins forces with Abel and Tres Iqus, a machine disguised as a human, to travel to Rome and seek answers regarding the destruction of her home. However, their journey will not be simple, as they must overcome various obstacles and uncover the secrets of Abel's past.