It has been a long week. I brought a few books with me to Costa Rica, and one was "I Am Legend" by Richard Matheson, which includes both the titular story, as well as several other horror and suspense stories.
Within the first two or three pages, I knew I was going to finish this book in one sitting.
One of my favorite things is when I know either the "what" or "why" of a book. This book does that, immediately letting the reader know they are reading about, not making them waste mental energy on figuring the story out. This book, in the first few pages, let you know you are reading a story about a person surviving in an apocalypse. This was a genre that wasn't even established at the time, but we know what is going on here. But the story lets us in and also gives us a sense of mystery and suspense: it isn't until sixteen pages in that we read the word "vampire", and then through a series of flashbacks and discoveries, we discover more fully what is going on.
We discover things at the same time as the protagonist: Robert Neville learns to use a microscope and raids a university library for books, trying to figure out whether vampirism is an infection carried by bacteria, or has a supernatural element. In between trying to figure out the mystery and finding and killing vampires in the daytime, he has to make supply runs and keep his home fortress secure. The book makes this normal routine a matter of tension, suspense, and horror: in an early scene, he loses track of time, and has to race back to his house before the undead awake. In movies or television, horror can be communicated with excess gore or jumpscares, but here Matheson manages to communicate the same sense of fear just by describing Neville's daily routine. The pacing of Neville's discoveries, punctuated by violence, is done perfectly. This was a real page turner until the final, twist ending.
So: this is Matheson, one of The Twilight Zone's most famous writers, and he has perfected the twist ending. In the last dozen or so pages of this 160 page novella, we get a revelation, of sorts, about the exact nature of vampirism. There were some hints throughout that things weren't what they seemed, but it is finally resolved, in a way, at the end. Although for me, the story was still ambiguous.
This is a classical horror novel in every sense, and also probably the first example of a "zombie apocalypse" story. Highly recommended.