Strange things are happening in Paris: almost every night, circles appear here and there, drawn with blue chalk. Inside each of them lies some old item—found in a trash container or picked up right on the sidewalk. Parisians think it’s a bad joke or the prank of a harmless madman. Nobody except Commissioner Adanberga believes the case can take a bad turn. And then, one night, in yet another circle, they find the body of a woman brutally murdered. However, the story doesn’t end there…