They found themselves standing around the rim of a pit perhaps half a dozen meters in diameter, and the same in depth. Marks in the soil made it obvious that this had been excavated with shovels, and vague footprints proved they had been wielded by humans and not robots. At the deepest part of the excavation, the gray soil had been stained red with rust. But the bottom of the pit was otherwise vacant; whatever had been rusting there was entirely gone. Only a few scraps of hard black plastic, and fragments of steel that had been altogether converted into rust, proved that Einstein hadn’t been lying to them all along.