The most unusual book in your house.

Here's a little project that everyone can get in on, which I got the idea for reading this comment from AllenS in The Glad Hand Café:

I have two of my grandfather's books. Automobile Electricity -- Starting and Lighting, and The Automobile Storage Battery -- It's Care and Repair. Anybody remember when you had to check the water in your battery? There are pictures of a visit to the battery factory. Looks like young boys were used in the cutting and grooving exide wood separators. Some of them are wearing ties. Almost everybody in the factory are wearing caps. The very back of the books is where you can order wiring diagrams for cars. Such as the Brisco, Cole, Glide, Pullman. Hard to believe how many different car manufacturers there used to be.

So what is the equivalent thing in your house (or apartment)? It needn't be old, just odd. Find your most unusual book or two and tell us about it, either here in the comments or separately on your own blog (with a link in the comments or emailed to me). A photograph of the cover or a page or something would be nice. I haven't figured out what my book(s) will be for this project. I got rid of all the books I didn't really care about a couple of years ago when I almost moved out of my house, so there's nothing that's just bad. I'm not really looking for bad, just unusual, like "The Automobile Storage Battery."

ADDED: My book is "The Sacred Mushroom and the Cross," by John M. Allegro. This 1970 book puts on a big show of scholarship to make the point that Jesus Christ was really a psychedelic mushroom.