The writing alcove at the back of the sanctuary was cut to Nessar's own measure, so that seated he could touch both walls with his elbows and the ceiling with the top of his head if he straightened. He had made it that way eighty years ago, when he still remembered what a cell with a sorcerer outside it felt like and wanted a small room that was his choice. It held a writing surface, two reading stones, a lamp, and a rack of small archive cases. It had no channel stone. Nothing the cells sent could reach him here.
Before he came in he had given one order at the passage mouth: no report was to come to him unless it held something the forty-eighth slate had failed to predict. The murmur of the outer passages bent around the alcove and stopped short of it. The heaps of slates were still on the reading-chamber floor where he had left them. He trimmed the lamp, ruled three headings in his narrow script, and began on the first.
The first heading was what the counter had used against him, and that part came quickly. Every cell had been trained to work one house through a fixed sequence until the possession held. The training rested on an assumption so old nobody had ever written it down: the family would not know what to do in time, and neither would the neighbours, the mosque on the corner or the people in the next street. For the first month that held.
It stopped holding the week Muhammad taught his method to the first ring of village workers. After that a schoolteacher could name the signs by the second night. A grocer could read the right verses over his own daughter before the cell had finished its third step. Nessar had read one set of field notes from the forty-second slate so often he could recite the cuts. A cell in a river town had worked a boy for six nights and lost him on the seventh to his aunt, who had learned the method at a meeting in a school hall four days before. The cell had done every step right. The aunt had sat by the bed all night with her finger in the book, keeping her place. He had tried, reading it, to picture the cell's last night: the operator pressing on the boy and meeting, where the protocol promised an empty, frightened house, a tired woman who did not raise her voice and did not stop. Nothing in the training covered a woman who did not stop.
The second flaw was his own design. He had built the network so that no blow to its centre could kill it. The cells did not know each other and the centre did not hold them, and no tribunal could cut off a head that was not there. Nobody had even tried. But the same shape that could not be beheaded could not be turned. The counter had closed houses one at a time across the whole spread of the lattice, and there had been no centre for the order to change course to travel through.
He wrote, "Correction built against the wrong threat," and looked at the line for a while, and let it stand.
The second heading took longer, because it was about the thing he had built and he had built it well. It had kept the long continuity alive. The fracture had run along the seams his theory gave it, the followers of winning gone, the followers of the cause scattered where they could be found again, the core at about one in ten and inside the band. Every failure provision had done its work. The design had answered three kinds of enemy: jinn law with its tribunals and arrests, human religion organised from above under a single command, and the lone practitioner who turned up once a century and held one village. All three it had survived.
Decades ago, in the margin of his theory, he had listed a fourth. He had judged it too unlikely to weigh and given it half a line: an enemy as scattered as his own, built on the same principles and at the same scale, around one figure who could build it faster than anyone could strike first. He found the half line now in the old case and copied it out whole, and under it he wrote a name.
Muhammad.
He wrote that the next design would need a defence against the fourth kind, and that the defence would look like nothing he had made before, and that its form belonged in another document.
One practical matter came before the last heading. For weeks, all through the decline, he had been changing the sanctuary's signature without telling a single deputy. He had moved the lamp hours by a quarter at a time. He had let the traffic at the passage mouth thin by one visitor a day. He had shifted his own reading and writing to the dead hours before dawn. No single change meant anything. Together they meant that anyone who had learned the leader's signature at the height of the surge, any of Soren's readers, any hunter with a grievance, would now look at this place and read an old jinn living alone in a small recess, one of thousands. He had cut that way out into the walls when he built them. He wrote two dry sentences about it for his own later reading and went on.
The last heading was the one that mattered. In a matter of weeks Muhammad had grown a lattice as fine as the one Nessar had taken eighty years to grow. Nessar had felt the pace of it in the seventeenth slate and the shape of it in the fortieth, and in the forty-eighth he had felt it finish. He set the stylus down. He picked it up again and wrote slowly.
"The construction was beyond any ordinary human of this generation. It needed something the human population does not hold in common. It comes, if at all, through particular figures, and we have no method for predicting them. This time the figure was Muhammad. The conditions that raised him, which our own operation helped to make, do not come back at short intervals."
He went on. "He has done his work. Whatever he does next, he will not build another counter against an operation of ours, because none of this scale will be tried while he lives. The next will be timed for a world where no such figure walks."
His hand kept moving after his mind had stopped telling it to.
"The Mahdi knew what this was. The next human who faces us will not have a Mahdi. We will not face a Mahdi again."
He read the three lines twice. Everything above them was engineering, causes and tolerances and ratios. These three were a declaration, and a declaration had no business in an operational record. He held the stylus over them until the lamp guttered and he had to trim it again.
He left them standing. The working pages would go into the operational archive, where whoever planned the next campaign would draw on them. The three lines would not. He took down the personal case from the lowest shelf of the rack. It was smaller than the others, its lid worn pale at one corner where his thumb always went. Inside were forty pages written across eighty years, most of them about the sorcerer who had owned him for forty years before any of this began, and not one of them had ever gone into a plan. He turned the top page over without reading it. It was the first he had written, the week he came out, in a hand so cramped he could barely follow it now: the price of bread in the sorcerer's town, the number of steps from the door to the circle, the sound the man's key made in the lock.
He blotted the page and laid it on the stone to dry before he would let it in. The ink on the last line was slow. In the lamplight it stayed wet long after the rest had dulled, a black ridge across the foot of the sheet: "We will not face a Mahdi again."