The Knights of Radiance informed the military of the rat nest where this wave of curses originated from. They went back on their journey, never informing of who they were and why they knew this.
They didn't even speak a word besides the knowledge they wished to convey before they started to look for more of these rat nests that might be hidden below walls, dug by rats, away from the eyes.
And this way, they found a total of two nests, each one deeper than the next and requiring even more effort to reach. But none of the knights made a sound as they acted in tandem like a well-oiled machine before digging through the dirt and blasting the magic formation one by one.
But the more they broke it, the more they noticed how futile their effort seemed. The curse had long spread and didn't even seem to depend on the formation anymore. It would increase in intensity as the night went on and there was no way to counter it.
At least not now.