We see the beginning of 'Four' in this collection which I found really interesting and I learned a lot about his character. It starts with his life with Marcus and the Choosing Ceremony. Through initiation at Dauntless and as an instructor we see Four grow, struggling with his memories old and new. His feelings for Tris are something new for him and we see how he acts the way he does, which I found intriguing. I find their relationship very refreshing. In this collection, Tris only appears in a few scenes in the last novella 'Four: The Traitor' so the focus wasn't shifted all too much towards what was going on there.
Anyhow, I really enjoyed reading Four's story. It was really refreshing to read as we got to see many other aspects of the factions and in particular Dauntless. Further more, we begin to see the holes in the faction system become more apparent in this collection.
Good read!