Viktor Nachtmahr is the bodyguard of Sera Reinhardt, the Princess of Germany, who is also a half human, half-vampire herself. It is a secret that must be kept in the shadows. By day Viktor protects Sera in the human world, but after sundown he protects her from the creatures of the night. Devoted to her mind, body, and what's left of his soul, the pure-blood vampire protects the dhampir princess from all sides without question.
But when Sera is kidnapped from her bedroom one night, Viktor discovers this is no normal heist, as ties to his past are brought to the forefront. Ties that he would rather leave forgotten.
His quest to rescue the princess takes him to a mysterious land on the far side of Romania, to a castle that is home to a vampire named Carmilla and her dangerous daughters. Carmilla has a plan for Sera, and she has to have the girl at all cost. With her army of monsters and even the castle itself at her beck and call, rescuing Sera will not be easy for her knight.
In spite of the dangers facing him in the chaotic castle, not to mention those who would be considered his 'allies', Viktor takes up sword in hand to bring his love home, safe and sound. His past be damned.