It was common knowledge that glass didn't just appear on its own in underground caves. Deep Layer creatures weren't necessarily capable of firing pottery, either, so these things had to come from humans—and it was unlikely they were made by the village's original inhabitants.
Kraft tossed aside the small shards of glass, put on his gloves, and sifted through the debris mixed with dust and gravel on the ground. He found a few larger fragments that had survived.
They were probably the thick, rounded bottoms of cups or bottles, with clear signs of having been crafted by hand. The workmanship was inferior to Wicham's, but after Kraft wiped away the dust, he could see the glass was relatively clear. Light passed easily through a thickness greater than a finger, casting irregular patches of light where the glass had melted unevenly.
He unbuckled his scabbard and used its tip to push aside the fragments of a large pottery vessel's belly. On the inner wall, he spotted residue somewhere between yellow-brown and reddish-brown.
He picked up a pinch. It had the scent of old metal that had lost its protective coating of oil, left damp for too long by poor storage until it was ruined.
The residue cracked and flaked away under light pressure, like slightly damp flour, scattering into dust. Some of it inevitably went up his nose, carrying the bloody, rusty tang of iron along with a faint, lingering sourness.
The uneven particles looked like ordinary rock. Minerals that hadn't been properly refined often left behind this kind of slag after being roasted.
"Rust powder?" Under Kraft's threatening gaze, William refrained from tasting it again. That didn't stop him from working out what it was; he often rubbed it off old iron fittings in the ship's cabins.
The captain had