Chapter 18 Zerabet

The ruined fortress at Zerabet had been built for a garrison and abandoned for a reason nobody had written down, and the reason, Zeyla discovered, was water. The garrison had held out through three sieges and then left in a single season, and the historians who had studied the site had assumed a treaty or a plague. Standing on the parade ground with the map in her hand, she understood that the fortress had been abandoned because its cistern had gone dry, and that a fortress without water is a wall with no argument behind it. The cistern was the answer. The nine observations converged on the center of the parade ground, and the center of the parade ground was a paved apron with a stone ring set into it, and the stone ring was not a wellhead and had never been one. It was the mouth of the cistern, sealed with a fitted slab, and the slab was the shape of a door. "It is under the ground," she said. "The shadow he measured from nine stations was cast along the line of this cistern. He did not hide the cache beside the road. He hid it under the one structure on the whole route that was designed to be full of water, so that anyone who found it and did not understand the road would assume there was nothing there but a basin." "And the water?" Tufan said. "Remember the water." "Remember the water is the whole key. Sarpel measured in shadows, and shadows need sun, and sun needs a sky without cloud, and the whole system depends on a dry country. He built his road for a land that was drying out. He knew the cistern would empty. He chose the one hiding place whose hiding depended on the land changing." She put her hand on the slab. "The answer was water, and the answer was that the water would leave." They had an hour, maybe less. Behind them, on the ridge, Sundur's men were working their way down. Below, in the direction of the camp, a truck engine started, and a second, and the sound of both began to move along the road that circled the fortress toward the main gate. Zeydan, and whatever was left of the consortium, and the five stones he had taken out of their packing before the raid, all of them converging on the same paved apron, because Zeydan had heard the same arithmetic and had reached the same conclusion by a slower road. She knelt and put her hands flat on the paving beside the stone ring and did the last of the arithmetic in her head, out loud, so that the two men could hear it and so that she would not be able to pretend afterward that she had made a mistake. Eight observations from the map, one from the shrine, each with its season and its hour, each converted into the length of a shadow cast by a man of average height at that latitude. She took the mean. She corrected for the drift between Sarpel's calendar and the modern one, which she had worked out three nights earlier in a shepherd hut, and which came to nineteen days. Then she reduced the nine bearings to a single intersection, and the intersection sat on the paved apron, and the paved apron was where she was standing, and the stone under her knees was warm from the sun. "It is a solution, not a theory," she said. "A surveyor who knew the hours could have found this in 1574, and a surveyor who knows them now can find it today. The only variable left is time, and we have perhaps forty minutes of it." She looked up at the ridge, where the figures of Sundur's men had begun to separate from the rock, and then at the gate, where the first truck was already nosing through the arch, and then at the cistern mouth beneath her knees, and she made the decision she had been walking toward since the morning a parcel arrived at a post office in Sarnem. She would rather read the method and lose the silver than hold the silver and never learn what it had been measuring. "We cannot lift this without a lever," Tufan said. "And we do not have a lever." Kulin sat down on the pavement with his back against the stone ring and looked at the slab, and then he did a thing that surprised Zeyla, which was to laugh. "We do not need a lever," he said. "You told me yourself. The stone was left by masons, and it is fitted, not mortared. A fitted stone in a dry country that has not moved in four hundred years will move for anyone who knows which corner to lift." He pointed. "Look at the joints. Look at the eastern corner. It has a gap. Every fitted floor slab in the world has one corner with a gap, because the mason leaves the tolerance in the corner nearest the wall." Zeyla went to the eastern corner and put her fingers in the gap, and Tufan stood over her and put his weight on the opposite edge with the flat of his boot, and the slab moved. It moved the way the first stone had moved at Tavras, easily, because it had been designed to be opened by a person who understood, and not by a person who was in a hurry. They had it open when the first truck reached the gate. Zeyla looked down into the cistern's throat and saw a ladder of cut stone descending into darkness, and below the ladder, at the limit of the daylight, a floor that was dry and pale and covered with a fine, even layer of dust. There was no water. There had been none for two hundred years. The cistern was a room, and the room had a door, and the door had been waiting since the winter of 1574 for someone to come down the ladder with a lamp and a reason. Zeyla went first, because it was her road. Behind her, in the courtyard, Tufan turned to face the gate, and Kulin sat against the stone ring with his hand pressed to his side, and the first of the trucks came through the arch into the parade ground in a cloud of dust, and a voice that she knew called out across the courtyard, calm and unhurried, as if the whole business had been arranged for his convenience. "Miss Arkut. I have the five. You have the four. Neither of us has the answer. Come up and let us finish this like professionals." Zeyla did not come up. She went down, into the dark, with her grandmother's notebook against her ribs and the last of the lamp guttering in her hand. ---