Nicholas meticulously chronicles Nazi efforts to obtain desired art from wherever it was, by just about any means necessary: outright confiscation, bribery, extortion, special military operations, &c. The efficiency with which Hitler and his minions gathered, transported, and stored the artistic masterpieces once held in private and public collections alike. She spends much time on Goering and his collecting habits, which bordered on the maniacal and sometimes even brought him into conflict with Hitler (and, as we've seen from the recent books on the van Meegeren forgeries, once or twice led him to purchase outright fakes).
Efforts by collectors, curators and dealers to protect their artworks also fall under Nicholas' wide purview; some of the steps taken are really quite remarkable. Here we learn of the vast removal projects that saw artworks taken from their comfortable galleries and stashed in remote chateaux, manor houses, even mines (with varying degrees of success, depending on the place).
Once Nicholas has managed to chronicle the dispersal of the art, she begins to put it back together again, tracking Allied troops as they took back territory from the Nazis (whose turn it then was to hide the art they'd pilfered from all across Europe), and the small core of "Monuments Men" who were tasked with protecting the found art. And then came the political and diplomatic rigamarole involved with determining how to return the pieces to their rightful owners, if they could be found (a process which continues to this day). Finally, she examines a few of the great treasures that remain missing to this day, perhaps still stashed in some sealed-off German salt mine, or hanging in a remote Russian dacha.
Dense, but entirely readable and completely captivating, filled with a cast of larger-than-life characters and great art.