This is an interesting book conceptually and I enjoyed it. I did think it was a little "preachy" however.
The premise is that everyone aged 22 and over is delivered a box with a string in it. The string indicates how long your life will be. No one knows where the boxes came from or how they got here, but everyone gets one. The implications are immense, of course. Start thinking about that in the context of your own life. Would you open the box? How would you change the way you live? How would this change society? Immensely! The author does a good job of covering so many scenarios as she follows a bunch of people's lives in the story. Most of the scenarios are good and interesting. There was one, however, that I thought was ridiculous (Jack and Javier) and I won't say why.
Anyway, I am glad I read it and I think it would be a good book club read.