That's the one word I can think of to describe this book. Complete and total bleakness. I don't think I've ever read a work of fiction so completely depressing and hopeless--there's no happy ending and not even a glimmer of hope for one. This is a book to read when you want to feel like you've been kicked in the soul.
The story follows a father and his young son as they make their way through an apocalyptic wasteland. We don't know how long they've been walking, though it must be years and years, as all the son can remember is walking down the road. We don't know where they're going, only that they have a vague hope of reaching the ocean. Everything around them is dead and burned, there's no color, heat or sunshine anywhere, and almost no people. They just walk, and try to avoid anyone who might steal their meager supplies. Every now and then they run into some horrible sights, and the book becomes even more bleak and depressing, which I didn't even think was possible.
McCarthy's writing is as dry and bare as the landscape he describes. It's actually kind of amazing how much he tells you in a few short sentences. There's almost no dialogue or characterization (the characters never even get names), but you still get a full picture of what is going in the story. Some scenes were horrifying not because of what he tells you, but just from what you can imagine from what little he says of it.
This was a very strange, depressing read. On the one hand, the story will leave you feeling a little empty inside (while also wringing your heart for the relationship between the father and son), so maybe you should avoid it because of that. On the other hand, you should read it for the brilliance of the writing alone. I wouldn't ever pick it up again, but I'm glad I did, because it was unlike anything I'd ever read before.