A Vertical Revelation

What happens when a brass plumb bob hangs motionless, pointing straight down into a nocturnal mystery? You investigate the bullseye, of course! Crouching low on the concrete step under the amber porch light, I followed the tapered brass tip down to the hairline fissure in the mortar. Did I already deduce the crack wasn't just weathering? Indubitably. Using the sharp edge of my copper key tag, I scraped away a thin crust of loose sand along the seam. The stone shifted half an inch with a dry rasp, exposing a tiny hollow containing a polished obsidian counter token etched with a spiral cipher. Who says nightfall brings an end to architectural inquiries?