Every now and then I like to read a non-fiction book to mix up my sometimes steady-stream intake of vampires, zombies, and the supernatural. Some non-fiction books, like The Demon in the Freezer are much scarier and fascinating than any bloodsucker.
I've listened to the audio of Richard Preston's tale of the history of smallpox three times now, and it never fails to impress with its detail and its scary story of the effort to eradicate the world's most volatile and dangerous virus ever. The story should have ended with the official removal of smallpox from the natural world in 1979, but like a bad science-fiction tale you know is going to end badly, the smallpox virus is still to this day kept in two official locations... that we know of.
Having grown up without the threat of smallpox, it's hard to fathom how this virus cut a swath through humans for most of our existence on a regular basis -- smallpox kills 1 in 3 infected and is spread through the air -- and how it's very likely that it is kept alive today in secret laboratories that are only trying to improve its effectiveness. Unleashed today, it would likely wipe out over 2 billion people. Conservatively. A fascinating tale of the greatest natural threat humans have ever known, and unfortunately may know again.