Saints preserve us! I've discovered my library has digital audiobook borrowing! I apologize in advance for the likely influx of guilty pleasure book reviews. 
 While it's been a few years since I read Divergent, I enjoyed returning to that world and learning more about Four (who I think I love/hated in the first book). This is another evil dad novel(la) though, so boo on that. Much as Tris undergoes the process of selecting her faction and beginning initiation in Divergent, Four's tale shows how he made his faction choice and earned his name. Fans of the series will likely enjoy this insight into a central character's past.