This is Sherlock Holmes, explaining the reason for his disguise:

I left the house a little after eight o’clock this morning in the character of a groom out of work. There is a wonderful sympathy and freemasonry among horsey men. Be one of them, and you will know all that there is to know. (“A Scandal in Bohemia”)

One of the many things I love about reading on my Kindle is that I can point to a word on the screen and immediately see how the New Oxford American Dictionary defines the term. (This turns out to be the same dictionary that comes bundled with Mac OS X, so I get the same definitions on both platforms.)

“Instinctive sympathy or fellow feeling between people with something in common.” I had no idea that “freemasonry” had this secondary meaning. I love it. I’ll try to slip it into casual conversation at some point.