Selling Flashlights To Save An Empire

The garrison at a frontier pass believes its general has found weapons sent from heaven. They are flashlights, headlamps, chains, fire extinguishers and a drone, paid for over the counter at a hardware store that is about to go under. The store's owner did not know what she was selling into. One night the general came through her back wall, wounded, and started buying. She rang up the sales and wrote them in her ledger, and as far as she was concerned it was trade, and trade that was keeping the shop open. He keeps coming back. On his side of the wall the northern tribes have closed in around the pass, the grain has stopped getting through, and a trap has been set. She goes on selling and keeping the books, and in between she and the general work out how to hold the city with what is on her shelves.