"What have you got for me?"
Nahash’s avatar stood before his general. The general shifted in discomfort. "Not as much as I would like, sir," he said, "but I have something."
Nahash motioned for him to sit. The general sat in a chair and unfurled a scroll.
"I assembled a team of scholars," said the general. "They couldn’t find anything in the histories. Neither the political nor the military histories contain anything like what you encountered. The spies were no help either. They found rumors and legends; nothing substantial."
"However," he said, "one bright young man thought my descriptions sounded like something from old tales he’d read. Folk tales, holy scriptures — that sort of thing. He did some digging and came up with two possibilities: angels and fairies."
Nahash stared at him for a moment. "Angels and fairies?"
The general took a breath. "Bear with me, sir."
Nahash stared at him for another moment. "Go on."
"The angel stories were useless," said the general. "They do sound much like the beings you fought, but there was nothing in there about how to counter them. Angels, in the old tales, pretty much just showed up and destroyed whoever the enemy of the day was."
"The old folk tales about fairies, on the other hand, were more interesting. They’re supposed to be able to change form and turn invisible, just like the things you encountered. A consistent theme throughout was that fairies have an aversion to metal — iron in particular. There’s stories of people putting horseshoes over their door to ward them off. There’s even a tale of a fairy being trapped in a brass lamp for a thousand years."
Nahash’s avatar looked off into space, then back at the general. "So," he said, "what you’re telling me is that these creatures who seem immune to all our powers might be hurt by hitting them with a rock?"
"I suppose so, sir," said the general. "So long as the rock had enough iron."
Nahash’s avatar vanished. You’re right, whispered Nahash into the general’s mind, it’s not much.
The serpent looked off into the distance. But it is something we haven’t tried.