Harrow set the stone with his trowel and counted it aloud, the way he counted every stone, because a stone that was not counted was a stone that might have been set twice.
“Four thousand one hundred and eighteen,” he said, and tapped the course home with the wooden mallet. The mortar was still green. He had mixed it himself at first light, from the lime that Pell had traded for in the spring, and it smelled of wet chalk and the sea, which was a long way off and had never once been a source of trouble to the south wall. “To the second string-course.”
The south wall’s lower course ran for a hundred and twelve yards beneath the Watch’s stair. Harrow had built the last six yards of it himself, after the Hold’s first wet winter had split the old cladding and left the rubble to fall into the ditch. He knew each stone by its weight in his hands. He could tell from the sound of the mallet whether the bed was level, and he did not like it when someone walked above him on the wall-walk while he worked, because the stones shook and the mortar lost its grip before it had set.
