1775. Commissioner Nicolas Le Floch is on a diplomatic mission to Vienna, ostensibly to deliver a bust of Marie Antoinette to her mother, the Empress Maria Theresa.
His real task, however, is to investigate the breakdown of French secret intelligence in Austria.
The city is a hotbed of plotting - and Nicolas only just survives an attempt on his life. On his return to France, Paris is in turmoil. The soaring price of grain and bread is causing widespread social unrest, and Nicolas' first police case is the unexplained death of a baker.
Could it be that events in the French capital are somehow connected to his experiences in Vienna...?