This second book in the YA "Divergent" trilogy follows the story of Tris and Four as they escape from the attack at the end of book one and seek shelter and allies within the other factions. The two of them struggle with grief, question whom to trust, and expose more secrets as the series progresses.I really struggled with the first half of this book. Tris's grief and guilt and secrecy over Will's death played a major part here, and created so much tension between Tris and her friends/allies that it made it a bit difficult to read. Her actions took on a recklessness and stubbornness that made me incredibly frustrated with her as a character. There was a lot of planning and debating and conspiring that progressed the story line, but didn't really make the reader feel like anything was actually happening.The second half picked up and became more what I was expecting as Divergent's sequel. The turning point seemed to be when Tris and Four finally started working together again, and although their situation takes turn after turn for the worse, at least stuff is happening and it's interesting. Some of the battle-type scenes were a bit overdone but there were some interesting twists and turns and at the end was a "revelation" that wasn't all that unexpected, but set it up nicely for the third book.