Hi all! 
 I'm one of those people who loves the Divergent trilogy. Having finished the series last year, I thought it could be a good time to pick up the side-stories written by Veronica Roth about Four. 
 I was not disappointed :) 
 Reading Four brought another side to the series that I had not exactly considered. It is true that in Divergent, Four often mentions his past (which I will not elaborate on due to spoilers) and leaves these facts ambiguous. This book of short stories helps understand his four fears, what his initiation was like, and how he went through Tris's initiation. 
 I really enjoyed reading the chapter about his initiation. You really see his 'evolution' from being very Abnegation-like to more Dauntless, as well as the development of other secondary characters in the Divergent series, such as Eric, and Shauna. I found it also really easy to understand why his main fear is Marcus through the first chapter, The Transfer. (BTW Marcus is a horrible fictional human being. Just sayin'. He's worse than in the series!) 
 *SPOILERS* 
 Through this book, you see Four in such a way that re-reading Divergent will change how you consider him. Whenever Tris describes him as being more ruthless and harsh in Divergent, the mirror created in Four really gives the impression that he is forced to be this way to pass initiation, and to keep his Divergent-ness hidden. For example, in Divergent, when he beats up Drew, he is portrayed as doing so somewhat heroically, menacingly, and harshly. However, in Four, the scene is extended, following him away from the scene, in shock because of what he had just done. I will honestly (re)-read Divergent very differently from now on. 
 *END SPOILERS* 
 This book, however, does not include any new facts about the series itself, and it should not be read as such. However, it is more of a complementary story to Divergent, which elaborate on many facts about Four. I feel as if this book, or collection of short stories, could have been separate chapters incorporated into the trilogy itself. 
 This collection was very fast and easy to read :) I do recommend that you read Divergent first though, especially the first book of the series.