With the load-bearing sag resolved, Jo Saye turned her attention to the most radical safety concept ever introduced to the city of Lathmere: the offering tear-seam.
Along the northern flank of the sleeve—the side facing the open waters of the turning basin—Jo used a sharp razor to cut a series of tiny perforations through the outer two plies of reed cloth, resewing the line with a single strand of unwaxed flax twine tuned to snap at exactly one hundred and fifteen pounds of pressure.
Master Dima watched with obvious distress, his hands fluttering over his beloved canvas. ‘Mistress Jo! You’re deliberately weakening the fabric! You’re cutting a wound into a sound sleeve!’
‘It isn’t a wound, Master Dima,’ Jo said gently, laying her hand on the elderly sailmaker’s arm. ‘It’s an engineered relief door. If the mountain flood hits with eighty thousand tons of head, something is going to break. If we don’t choose where it breaks, it will tear inward toward the narrow high walkway, drowning Eren and Pella in scalding sulfur water. But if we give it this tuned seam, the canvas will tear outward into the basin, bleeding the excess water harmlessly into forty acres of lake while the crew steps safely down the ladder.’
