First book, (outside of heresy) that I believe truly worthy of 5 stars. The Iron Hands where amazing and nothing that I had expected. There where some interesting twists if you are similar with pre-heresy and the Emperor's Children its a must read.
*Spoiler*
My only regret is that they didn't make it a bigger deal that chaotic Emperor's Children where around. More of them fitting there most extreme enemy would have been even better.