Hunter Ella disguises as a thrall to infiltrate the vampire castle and kill the bloodthirsty tyrant Lucas to save her sister. But she finds out Lucas has been secretly protecting humans, standing against his cruel father and the radical vampires. When a trap forces her to poison him, she takes the hit instead, reveals her true identity, and teams up with Lucas after he awakens his Primordial Bloodline. Together they crush the conspiracy, abolish human enslavement, and rule side by side.