It is always interesting to see the way that a book starts. This starts not only with a preface by the author trying to explain why the subject of the story Michel does not conform to the usual pattern of a hero or villain and then has an italicised explanation that his three oldest friends gained the following account from his own lips.
The idea of a non traditional central character is interesting and Gide is clearly trying to warn the reader that although not good Michel is far from being totally evil. There is a decision that needs to be made about his actions that is for the reader to take.
Having gained your intrigue things start with Michel explaining to his friends that he has not seen them since his wedding and that he has called them together to explain himself. You sense there is some calamity that has happened in the relatively short time since they last met in the church on his wedding day.
Tomorrow might bring an idea of what has happened…