An experiment that took place 150 years ago, resulted in Elizabeth Iris Nightbloom becoming a vampire and a war puppet for the human government. Unable to escape from the human government, she continues to be their war puppet that defends mankind from the Supernaturals.

Vampires and Werewolves are blessed with longevity, strength, and wisdom, while humans were cursed with greed. Unable to accept the fact, the humans' greed blinds them from what they do have and curses them to want to rule all.

As normal, Elizabeth will complete the tasks and missions given to her, with no fail. But when a mission is reported as a success, with questioning results, the human government's doubt in Elizabeth grows and what has been kept silent starts to reveal itself.