Every few hundred paces something boomed and rumbled in the depths, a noise Barrick could feel more than hear through the creature’s muffled perceptions.

What is that noise? It sounds like thunder—or cannons!

You are closer with the second. Gyir was silent for a moment as the creature stumbled, then righted itself. It is Crooked’s Fire, or at least so we call it. Your people call it gun-flour.

Then they truly are shooting off cannons down there?

No. I suspect they are using it to dig. Now let me concentrate.

Down and down and down they went, until the guard-beast reached a room where corpses were being loaded into the huge corpse basket to be winched to the top by more of the neckless, mushroom-colored men. The dead were being unloaded from ore wagons pushed by more servitors, and the guard-beast followed the dirt track of the wagons down into darkness.

They were still descending, but this slope was more gradual so that the haulers could push their carts up it. The wagons were not just bearing bodies, either: at least ten times as many were coming up from the depths full of dirt and chunks of raw stone, but these were being rolled away down another branch of the tunnel.

Barrick could almost feel Vansen and Gyir trying to make sense of the arrangement, but he was already feeling queasy from the depth, the heat, and the frequent rumble of the concussive, hammering sounds farther down in the deeps. If they put me to work here, he thought, I wouldn’t last long. Barrick Eddon had fought all his life against being called frail or sickly, but living with a crippled arm had made him hate lying to himself as much as he hated it when others did it to soothe him. I could not do what these creatures are doing, working with hardly any water in this dreadful, dust-ridden place. I would die in a matter of hours.

The guard-beast trudged downward into an ever increasing throb of activity. The inconstant thundering of what Gyir called Crooked’s Fire was much stronger now, so loud that the staggering guard-beast almost fell over several times. Hundreds of prisoners pushed carts past him up the long, wide, sloped passage, but no matter how monstrous their burden, they always moved out of the guard-beast’s way.

At last Barrick saw the end of the passage, a huge, low arch at least twice as wide across as the Basilisk Gate back home. When the guard stepped through it into the cavern beyond, a monstrous chamber which dwarfed even the cave that housed the corpse-pit, Barrick could feel hot air rush up at his host, tugging the matted fur, bringing tears to the creature’s already blurry vision. A line of torches marked the broad track down through the swirling dust and marked off the cross-paths where other guards and prisoners labored with the weight of ore carts. To Barrick each step seemed to take a terrible effort—the powerful discharge of hot air he had felt at the doorway continued to buffet the guard-beast at every step, as though he walked down the throat of a panting dragon. It pressed at Barrick’s thoughts like crushing hands and Barrick thought he might faint away at any moment, simply swoon into insensibility like the frailest girl-child.