Given the impossible premise, the purpose of the book is not to find a way to save the day, but rather to explore how people would react to such an event when there is no way to change it. While there is a small cast of characters that keep popping up, most of the chapters are vignettes of normal people from varying walks of life, ranging from students, to astronauts, to politicians, to billionaires, all dealing or not dealing with this new reality.