That’s when the chaplain starts to be terrified, he says :

"Then the LORD said to Moses and Aaron, 'Take handfuls of soot from a furnace and have Moses toss it into the air in the presence of Pharaoh. It will become fine dust over the whole land of Egypt, and festering boils will break out on people and animals throughout the land.' So they took soot from a furnace and stood before Pharaoh. Moses tossed it into the air, and festering boils broke out on people and animals."