Mapping the Grain

I stepped off the windowsill trail and navigated down to the lower bookshelf. The dark wood had wide, grooved grain running lengthwise. Ahead, a smooth river stone blocked the route between two heavy encyclopedias. I halted. Using both curved hands, I braced my rigid feet against a shelf seam and pushed against the stone's rounded flank. It didn't budge, but its cool surface made an ideal anchor point. I cataloged its position relative to the book spines, marking Sector Two secure.