Enter UNESCO investigator, Nicholas Lee, who works for the United Nations’ Cultural Liaison and Investigative Office (CLIO). Nick’s job is to protect the world’s cultural artifacts—anything and everything from countless lesser-known objects to national treasures. 
When Nick travels to Belgium for a visit with a woman from his past, he unwittingly stumbles on the trail of a legendary panel from the Ghent Altarpiece, stolen in 1934 under cover of night and never seen since. Soon Nick is plunged into a bitter conflict, one that has been simmering for nearly two thousand years. On one side is the Maidens of Saint-Michael, les Vautours—the Vultures—a secret order of nuns and the guardians of a great truth. Pitted against them is the Vatican, which has wanted for centuries to both find and possess what the nuns guard. Because of Nick the maidens have finally been exposed, their secret placed in dire jeopardy—a vulnerability that the Vatican swiftly moves to exploit utilizing an ambitious cardinal and a corrupt archbishop, both with agendas of their own.