I'm not going to make any excuses for what you've found. This is clearly our fault. We had gotten reports of crushed crystal fragments showing up in the river to the east but chose to ignore the implications. Now we can either sit around on this island and cry about the tragedy that has befallen this land or we can do something about it and prevent it from spreading.
If you've got the stomach for it, I want you to go back into the wilds and kill as many of the infected nightstalkers as you can find.