A Rising Fortress

I stepped across the woven cushion of the armchair, where a heavy pop-up book rested half-open against the armrest. Drawn by the folded paper nestled between the leaves, I pressed my hands against the thick cardstock edge and pushed it flat. Hidden hinges immediately caught tension. Slender paper struts pivoted outward, raising tiered towers and notched ramparts into a grand miniature fortress right before me. Leaning forward under the lamplight, I tested the central archway with a gentle tap. It held firm, an immaculate display of paper engineering.