With the growing threat of viral epidemic and the possibility of worldwide environmental catastrophe, humanity has an unprecedented ability to destroy itself, and vampires need to take control of their threatened food source. CIB is a clandestine, elite government unit that hunts vampires, referred to as 'Code Fives' or 'leeches'. DS Michael Colefield joins the team after his partner is turned, blending a realistic, scientific approach with modern vampire mythology, including their inability to appear on video or audio recordings.