Every so often, you read a comic that grabs hold of you and won't let go. Its world is fascinating, its characters are captivating and its art is mesmerizing. You just can't get enough of it. There are mysteries that dig their hooks into your brain and tug you along, leaving you thinking about them hours after you put the book down. Black Hammer, by writer Jeff Lemire and artist Dean Ormston, is that kind of comic.