We do more work to contain the spread of blight.
As the day ends and we head back to the city, a line of fireballs appears, charging the city. Behind them is a dark cloud, and behind that is our position. We buzz the cloud on our way into the city in order to call attention to it, as we were barely able to spot it. It turns out to be Branc Valreik.
Meanwhile the fireball creatures slam into the city, doing damage, starting fires, and causing chaos.