At just under 300 pages, Black Moon is like a fast-moving train glimpsed through a window. (Sorry if that sounds strange, but I find it helpful to think visually about a book I've just finished).
Let me explain. Imagine glancing out of a window at night and seeing a train rushing by, but you can't see either end of it. You hear it and see the flashing lights, and you know that it's moving, but that's all the information you have. Your first question might be, "How long is this train?" or "Where is it going?"
That's right- we are given no explanation for how and why the epidemic began; however, one character does muse on this particular topic for a couple of pages: "Maybe it was the toxic dust from fallen towers...Maybe it was some ancient spore released by the melting ice...Maybe it was the rewiring of our minds..." But there is ultimately no answer.
And there is no solution; at least, not for the long-term. Between these two poles wander characters in various stages of the sickness, including one man who seems completely immune. All around him, the people who have stopped sleeping go insane, wandering around confusedly, throwing things out of windows, mumbling to themselves, violently attacking anyone they find sleeping.
The one oasis of sleep left within the realm of the story is a Sleep Research Center at a California university. After some trial-and-error, the doctors devise a way of jump-starting a part of the brain that controls sleep. Unfortunately, the dreaming part is left out, and as one of the doctors warns, it is the dreaming that makes us human and keeps us human. Without dreams, we melt back into our ancient origins and everything we've invented and created will disappear.
The one element that gives this book its particular and unique brand of creepiness is the scrambled language spoken by the sleepless. Calhoun masterfully constructs near-meaningless sentences that sound like prophecies from an oracle. This is supposedly how someone would speak if they stopped sleeping, and for some reason it made my skin crawl (in a good way).
Ironically, I stayed up late and woke up early just to read this book, because it was that good, that haunting. Go read it.