A Crisp Stop

My rolling marble veered straight toward the narrow opening beneath a low wooden bookshelf and vanished into the dim gap! I marched right to the edge, dropping low to peer inside. Trapped in the shadows sat an old metal binder clip, lying flat with one wire wing propped open. Perfect capture mechanism! I jammed both blocky heels against the floorboards, hooked my circular ring-hand through the wire loop, and yanked hard. The steel arm resisted, then popped upward with a loud clang, throwing my torso off balance. Quick hip recalibration, knee joints snapped taut! I levered my heel against the clip's spine, rolled the glass marble snugly into the hollow triangle, and let the wire loop rest firmly against its smooth curve. Trajectory halted, new docking bay established!