The beautiful medieval architecture of Bruges belies the dark longings of her residents. When the wealthy and powerful Ludovic Degroof’s jewelry store is broken into, nothing is stolen, but the jewels have been dissolved in jars of acid so strong it can even melt gold. In the empty safe is a scrap of paper on which a strange square has been drawn. But when Degroof’s offspring also receive letters with this same square, Inspector Pieter Van In and the beautiful new DA Hannelore Martens find themselves unraveling a complex web of enigmatic Latin phrases, a baroness’ fallen family, and Degroof’s relationship with a hostage grandchild, who has been ransomed for a priceless collection of art.