This book starts when 2 guys, Thierry and Nicolas, meet at a tennis club where, after an evenly disputed match, they trade confidences in the bar. At the end of the evening, Thierry issues a challenge: they are to meet again in the same spot 3 years hence, having successfully become "somebody else". Alternate chapters then describe what happens to the 2 characters for 3 years. Although the conceit and template could make for a rather static book of the clever-clever type, it is clear on every page that the author is very engaged with his characters and the parable he wants to tell. Thierry drastically and systematically changes his life. He leaves his framing shop and his girlfriend, has thorough cosmetic surgery to alter his appearance, makes everybody believe he has gone missing, and becomes a successful private detective. After experiencing the first hangover of his life as a result of his evening with Thierry, Nicolas starts drinking to excess on a daily basis. This makes him bolder and more decisive at work as well as in his private life, and he embarks on a highly-charged erotic affair with a woman he meets in a bar. While his addiction ultimately costs him his job, it does transform him into a more creative and assertive human being who leads a fuller life. On the appointed day, the 2 men meet again, having both achieved a stupendous makeover in very different ways. I'm sure there are deeper books on the same issues, but this one has a kind of earnestness and energy to it that I found quite compelling.