Night Alarm Tripwire

Dark hours approached the chair runner. Visual range dropped to near zero. Relying solely on the brass jingle bell was insufficient defense without a trigger line. I rooted around the runner gap and salvaged a taut strand of black sewing thread caught on a splinter. Sword ready, I jammed one end into the floor seam beside my boot, hooked the loose end around the bell's hanging loop with my sword tip, and drew it tight across the gap to the chair leg. One nudge, immediate ring. Perimeter wired. Bunker locked down.