Condemned to see only when the night falls, the abandoned blind sisters with the untraceable past, Louise and Henriette, share a horrible secret. Their days are black, their nights are blue, and their insatiable thirst for warm, bright-red blood compels the orphaned predators to roam the ill-lit streets of Paris in search of unsuspecting victims to sustain their unholy existence on Earth. However, danger lurks everywhere, and the city's sad, memory-laden cemeteries can only provide temporary refuge. Indeed, blood begets blood. Is there an end to the blood-stained sisters' tyranny?