And to be clear, these creatures which are infesting Fall River . . . I do not believe they are fairies. They are not ghosts, or elves, or gnomes, or demons. They are not brownies or bogies. But when I read about such mythic monsters, I detect a glimmer of some similar sentiment—an undercurrent of truth, a glimmering seam of gold buried in a worthless boulder. I read about peasants, priests, and alchemists in days of old who had codified their superstitions into wards, hexes, potions, prayers, chants, songs, and systematic protective behaviors in order to keep themselves safe from dastardly influences. They were testing the boundaries of unknown things, attempting by trial and error to manage the stuff which goes “bump” in the night.

They were the scientists of their times, these people. They experimented with dark forces and dark creatures by choice or by desperation, combining and recombining the things they knew with the things they suspected—fishing, always fishing, for a reliable inoculation against evil.

I skimmed a few pages, running my finger down the lines until I found what I’d dimly recalled from earlier readings.

One thing and one thing alone is certain with regards to foul specimens of the dark court fey: They fear and loathe contact with any rusted item, be it tool, or lock, or ornament. They eschew the touch of this substance, recoiling as if burned or otherwise contaminated. In some rural counties, where the friendly assistance of nearby neighbors or peace officers is not readily at hand, nails are left in the rain to rust—then gathered, collected, and pounded into doorways and windowsills as a barrier against entry by any unwanted supernatural creatures. A barrier such as this is considered to be one hundred percent effective, and utterly foolproof.

I found the “foolproof” bit unlikely, but this small, overwrought paragraph gave me much to think about. The author proposed that the critical element is rust. Rust does not occur without the presence of iron. My axe was not at all rusty; I kept its edge ground fine and its surface well cleaned. Yet still, I noticed a reaction. A difference. A significant improvement in efficiency, as compared to other instruments.

“It’s not the rust,” I argued with the book, and its long-dead author—should his disapproving shade be present. “It’s the iron itself.”

I considered the implications, if there were any. My bedside candle flickered and steadied, along with my thoughts. When first I’d read Dr. Valant’s mention of the nails, I’m sure I thought it was frivolous. A fallacy of the poor and uneducated, a superstition without merit.

Now . . . I was not so certain. The two things, iron and rust. One known to be effective, one claimed to be. Did it matter that I did not understand the mechanism by which it worked to prohibit monsters? Not if it worked regardless.