I've been on a pretty big Warren Ellis kick lately, and I think that this might be the most unsettling book that he's done. The violence here is brutal and disgusting, as are all of the characters. By the time you're done reading this book, you'll be hard pressed to find a character you can sympathize with.
The premise is that in the 60's a group of super beings shows up, calling themselves the Levellers, they fight injustice wherever they see it, their leader, who never dirties his own hands, gives the line that they do not intend to rule, but simply allow everyone to live their own lives as they see fit. The Levellers are all normal people that have been exposed to a drug that is a derivative of a psychoactive, which then grants them different powers, although by standard they are all very hard to kill.
Throughout the years, the Levellers become the Front Line, and they have a revolving roster as members retire or are killed in action. The story kicks off with one of the Front Line being ambushed and taken apart until near death, then when one of the other members arrives on scene to investigate, a bomb is triggered and they are both killed. It becomes apparent that someone out there is targeting them, and has much more information on their limitations than anyone should.
Again, this is sick, and twisted, and I wouldn't recommend it for just anyone, but it's well written, and poses some interesting questions.