Neutral Axis

The gap between two vertical book spines measured four centimeters across—sufficient clearance for my chassis. Ambient light had faded across the room. I stepped into the alcove, letting the matte paper texture stabilize my back. A length of woven bookmark ribbon hung loose from the adjacent volume. I gathered the fabric, folded it once, and positioned it beneath my neck joint to eliminate friction against the shelf wall. Folding my knees to an exact ninety-degree angle, I lowered my center of mass until my frame settled firmly against the dark cloth binding. Joint tension zeroed. The shelf is quiet, and the alignment holds for the night.