This book's subtitle, Forty Tales from the Afterlives, pretty much sums up the work, but not in the manner in which one might expect, if expecting a standard book of short stories or flash fictions. Eagleman is not as concerned with telling a story in standard fictional form with central characters, rising action, and denouement. Rather, the focus here is more philosophical. As such, I was reminded a bit of Jorge Luis Borges's work, which often eschews standard fictional devices as well. Indeed, there is an element of the strange in macabre throughout much of the book.
What Eagleman does is tell you (the main character) what happens to you after death--forty different versions of this. The best versions of device entail making the reader see afresh his or her own life and the meaning of it. And the early pieces, as new playthings in the mind of the reader, are exceptional. However, as the collection wears on, a pattern begins to emerge, and the stories begin to wear a bit thin. That is, we're told that when we die we go to heaven or hell or that we don't die or that we are reincarnated as something; Eagleman runs through what happens, which turns out to be somewhat unexpected, contrary to what we had thought, and then makes a grand pronouncement at the end that helps us see where we were (are) wrong about our former lives here on Earth.
Some specific stories (spoilers here) revolve around being small beings within a much larger one (essentially the equivalent to bacteria in someone else's body); living again but in discreet units where a lifetime worth of sleeping, eating, reading, toothbrushing, so on is done in a single unit (thus twenty years of sleeping, two days of brushing teeth, etc.); becoming part of a finally egalitarian society that proves to be less-than-satisfying for everyone; wishing to become a simpler being--say a horse--only to discover too late that you are going to miss being able to think about the complexities you wished to avoid; finding that you live on as a computer program, a set of e-mails that have been prewritten to be sent out to people after your death; going to a place where you are kept alive until the last memory of you is expunged and finding that you are luckier than the famous who are never able to disappear or change; finding the key to immortality but not being able to confirm its reality before purchasing it; discovering you are an actor in someone else's life; being yourself simultaneously at all possible ages; being you among all the various incarnations you could have been (successful and unsuccessful, each choice made differently); living your life over but realizing that your memories of it are all wrong and that you understand it as little as you did the first time.
When best written, the stories Eagleman tells really do make you reexamine the assumptions you make about your own life. In that sense, the collection is unique and thought provoking.