The best thing about Clive Barker is the worlds in his head.
I've read a few reviews of his books that have suggested that, at least in his shorter novels, details of setting and character fall by the wayside. I actually agree with them. In Cabal, for example, I found myself wanting to know far more about Midian, the city where monsters take refuge, than the novel tells you. What sorts of monsters abide there? When, why, and how did Baphomet create it? There's so much room for more mythology.
In the end, though, it's that room that makes his work so good. Midian is an idea, and a wonderful one, that gets your mind playing with the whole idea on its own: What, and who, do you find in a city of monsters (called "Nightbreed" in this novel)? How do they live, feel, think about their world and the world of their human prey? It works because while perhaps you want more detail, you don't necessarily need more answers.
The plot focuses on one monster in particular, a man named Aaron Boone, who falsely believes that he has killed many people during psychotic breaks. Thinking himself a monster, he seeks the abode of monsters, and finds his way to Midian. While he is innocent at the time, one of the Nightbreed bites him. Soon after, he dies. Because of the bite and the circumstances in which he dies, he becomes a werewolf-zombie-creature (more interesting than it sounds, I assure you) after his death. In his new form, he is accepted into Midian, and that's when things get interesting.
The story ultimately pits Boone and the other monsters of Midian against the human world from which they've taken refuge. Boone rescues his human lover from the Normal world's version of a monster, a serial killer who hides behind social decorum and a button-eyed mask. Unfortunately, he risks Midian's discovery in doing it, and the sanctuary of the Nightbreed is no longer safe.
The story is fascinating, and Barker does a good job of showing us the difference between the monsters' world and the normal world. He easily creates sympathy for the Nightbreed, who come out at night to prey on the normals, but would never seek to exterminate them. Humans, of course, are less kind to monsters.
It's a good story, but as I mentioned, I wanted more about Midian, the monsters, and their lives. We're told that utter secrecy is Midian's most important law, and we guess immediately why. However, we don't know exactly why Midian was created, or much about Baphomet, the creature/god who created it.
I also didn't much like Button Face (the human murderer), and I can't tell whether this is good or bad. On the one hand, the point is precisely that a crazy guy who gets excited cutting people up has nowhere near the past or the poetry that a werewolf or vampire, steeped in attractive mythologies and centuries of human fascination, has.
On the other, though, the character without his mask was fascinating in his own right: cold, calculating, and civilized. The most frightening thing about him was precisely that he wasn't a monster, at least not one like the Nightbreed. The Nightbreed were violent and ruthless because of what they were: Other. They were not human, or at least no longer human. Their violence was the violence of predation. But the monster in the humans' midst had no such excuses: he was simply cruel, and liked it that way.
I felt that the addition of the button-faced mask, and the voice bidding him kill (though he seemed to like doing it well enough without the voice's promptings) did set him up as a slasher-type. However, it made him fantastic in his own right. His own strangeness, as obviously clichéd as it was, made the distinction between his peculiarly human cruelty and the bloodlust of the Breed less sharp. I understand why Barker set the character up as he did, but part of me wishes he hadn't.
Overall, "The Sympathetic Monster(s)" has been written before, and will be again. Barker's version of the story is especially good. While he makes us like his monsters and hate the humans who persecute them, he doesn't fall into the trap of making the monsters pitiful. We don't pity them so deeply that we lose any sense of their monstrosity. Instead, we learn and examine, along with his human characters, how to see through monsters' eyes. He balances what they are with what we learn when we see their city and know their side of the story, and it all works quite well. While some flaws and stylistic choices irritated me, I'd definitely recommend this one. The concept is simply so interesting and so well done that it's worth reading and exploring Midian for yourself.