I saw the grave of Charles Williams, in a little graveyard in the heart of Oxford, before I read his novels, but I always knew I would need to get around to reading them some day. So War in Heaven is the first I've read. I expected it to be rough around the edges, because it's his first novel. I'm not sure how much of the roughness is from first-book jitters, or from the general distance in reading novels 100 years old (not composed by masters of their craft), or from something unavoidable in his writing that explains why he may be the least popular of the Inklings (well, it's probably down to him and Barfield). Is it all three?
But as I got more used to Williams's idiosyncratic voice I found sentences, character traits, and whole scenes that shone with a light that speaks of very real things, things that are normally glimpsed through a mirror darkly. This particular story has to do with the Holy Grail and Prester John and dark rites. There's something very modern and Hollywood about the subject matter, and yet the way it develops is exactly the opposite of Hollywood tendencies (and I mean that as a sincere compliment). There are moments of disturbing darkness in this but also moments of clear, illuminating light. To call it a thriller would be to emphasize not the former moments, but the latter, and that's what I found most surprising about this story. The light is thrilling. That's a very special trait in a writer.
As for what this story seems like, it's most like CS Lewis's That Hideous Strength, although I must say that I liked War in Heaven more than Lewis's novel, which always felt over-the-top and unrealistically characterized to me. Williams writes "good" characters that are both more serene and more convincingly doubtful than Lewis's characters, and "bad" characters that seem both more evil but convincingly so to me. Granted, Lewis is clearly a better writer, I'll definitely give him that. But enough about Lewis. Williams's story is also strangely like a modern movie and even has elements of Alan Moore in its use of supernatural darkness and occultism.
My advice is to get past the rough parts and odd writing and to look for the lucid moments, which are worth it when they come. I'm looking forward to the rest of Williams's novels in the future, and he's definitely a worthy member of the Inkling crowd. In fact, for some kind of people (the type who read Alan Moore comic books, and I'm looking in the mirror when I say that), Williams offers a combination of themes and characters that I have not found anywhere else.