Each of the stories focus on a different character in a different location. While it isnt explicitly revealed early on in the series, throughout the progression of the series it becomes clear that all four protagonists are related to one another, although none of them know about the lives the others currently lead and have not seen one another in years, if at all. Alex (#1-3) is the father of Jack (#4-6) and Ethan (#7-9) and Adam (#10-12) are Jacks twin sons. The locations the stories take place in are New York City, Miami, Detroit/Midwest, California/Nevada. As the latter two stories deal with the protagonists traveling, they arent confined to a single city.