Four Stories for Four
This book is called Four: A Divergent Collection. It is a collection of short stories set in the Divergent universe about a character named Four. In a clever bit of (perhaps unintentional) wordplay, there are four (4) stories about Four (the character) in Four (the book), not counting the three scenes from Divergent that are only a few pages each. These show scenes straight out of that book, but from Four's point-of-view.