Appearances can be deceiving, and in a century where they often play the monk, the young Marie-Anne De La Tour, a 22-year-old minor noble, will learn it the hard way. Her curiosity will push her to send a letter to a convict of the same age, which will put her face to face with a reality that she has known for a long time, but which she refuses to be confronted with. When the nobility meets the third estate at the very end of the 17th century, they can have so much to say to each other that one detail can upset two entire lives until it reaches the point of no return.