I'm going to liken this book to putting your hand in some boiling water. Of course the waters cold at first. Or else you'd just reflexively pull your hand out. So the water's cold, but then it slowly starts to heat up. You don't really notice at first and then next thing you know the water's boiled and your hand's blistered and you've realised all to late and suddenly the damage is done.
Now imagine the water is the violence in this book. We start off with an axe to the head, progress to a fiery explosion and some brutally mauled bodies, divert momentarily to domestic abuse and a spot of violent sport before finishing with an all out bloody rampage.
Mr Abercrombie you are one insidiously evil genius.
The story follows 3 main characters, none of whom are particularly likeable and yet are somehow likeable all the same. Glokta, a member of the Inquisition (think torturer meets investigator) is a slightly sadistic cripple. Jezal dan Luthar is a selfish, elitist brat training for a fencing contest. Logen Ninefingers could almost be the "hero" of the story but then he too is flawed by a bloody past spent earning a bloody reputation. Everyone - even the supporting cast - is dramatically flawed in one way or another, brilliantly fleshed out and so god dam intriguing it's like watching a car crash.
In terms of plot, this book is definitely just the beginning. Each separate storyline slowly weaves it way together and suddenly you've reached the end and some crazy guy has just snatched your half eaten sandwich and you must get it back and now I must buy Before They Are Hanged to find what the other half tastes like.
My money's on delicious.