Paris. At the bottom of a cellar of a building in Belleville, twelve bodies are found dead, bloodless.
 The 36 is on the breach.
 These facts remind Captain Julie Delorme of her first crime scene, thirteen years earlier , that of a child apparently suffering from dementia who had killed his parents to feed on their blood .
 Convinced that there is a link between the two cases, Julie will face her oldest demon and embark on a high- risk investigation.