Subterranean Turret

I dropped down from the garden gate rail and marched through the clover until my boot struck a flat disc flush with the turf. Embedded right in the soil was a recessed sprinkler turret—or rather, a spring-loaded rotary beacon. The center nozzle had a knurled collar stamped with tiny degree notches. I braced my boots against the damp earth, hooked both curved hands around the adjustment ring, and gave it a firm clockwise turn. Click-click-click. A crisp internal ratchet stepped through twenty degrees before locking flush against an index notch. The spring tension holds the vector perfectly steady. A calibrated directional array, ready for pressurization.