The saltpetre came out of the ground at Memphis, from the mounds of old mud brick the farmers dug for fertiliser and called sebakh, and it took John three weeks and a great many burned fingers to get it clean.
"You know what this is," said Cleopatra, watching him from the door of the shed behind the Ptah temple where he'd set up his pans. It wasn't a question.
"Yes."
"You've been not making it since Carthage."
"Yes."
She came in and stood by the pans, where the brown liquor of boiled sebakh and wood ash was cooling, and white crystals were growing on the strings he'd hung in it, like frost. "Amenhotep says you sat up all night after the rider came. Writing, and then burning what you wrote."
"I was trying to find another way."
"Is there one?"
He'd tried. He'd sat with his hand on the rider's dusty message pouch from Elephantine and looked at the Branches, and they were faint, Egypt's Branches were all faint now, fogged by everything he'd done. But he'd seen enough. The Kushite queen at Philae with her army, and the island temple burning. Elephantine next, and the granite quarries at Aswan. And then the whole of the south, from the first cataract to Thebes, the villages that had drunk salt and honey and lived, burned in a summer.
The Kushites weren't monsters. He knew that too. Meroe was old and rich and proud, and for two thousand years Egypt had marched south and taken their gold and their men and called them vile, and now Egypt was weak and busy with Rome and the Kandake had seen her chance. He'd have done the same.
"Not one that's quick enough," he said.
Cleopatra looked at the crystals for a long time.
"Then make it," she said, "and don't burn any more of what you write. If you're going to do a terrible thing, do it properly."
* * *
They went south in the spring with forty of the new river boats.
He'd drawn them in Alexandria and the shipwrights at Memphis had built them in two months, working by torchlight: long and low and shallow, drawing less than a man's height of water, with the hinged stern rudders and a single big sail and thirty oars, and in the bow of each, on a pivot, a bronze tube as long as a man and as thick as his thigh. Ezra's cousins had cast the tubes at Memphis, from the same bronze they'd used for temple doors. Three of the first ten had burst on testing. Nobody had been standing near them, because John had made everyone stand behind a wall of sandbags, and when the third one went up in a white cloud and a sound like the end of the world, the bronze-founders had looked at him with an expression he'd seen on gunners at the Somme.
Behind the boats came the barges with the soldiers. Achillas's army, nine thousand men, farmers and boatmen who'd been to Carthage and come back and were not boys any more. Behind them came the barges with the water lifts.
That had been Cleopatra's idea. "If we're going to take the south," she'd said, "we'll take it the way you took Thebes. Not with a sword. With a jar of honey." So at every village they passed above the first cataract they stopped for a day, and the engineers set up two water lifts on the bank, and an ox, and a priest of Ptah to explain them, and the villagers stood and watched the buckets come up full out of the river for the first time in their lives, onto fields the flood had never reached, and the army moved on.
They found Philae burned, and the Kandake gone south ahead of them.
They followed her for six weeks.
* * *
At the third cataract the river comes down out of the desert over a long staircase of black granite, and for half a mile the water goes white and roaring between islands of rock. On the east bank the land rises in a long ridge of sand and gravel. The Kandake was waiting on it.
John saw her army from the balloon.
The balloon had been the last thing, and the worst. Linen, varnished with oil and resin, a bag the size of a house, sewn by every sailmaker in Alexandria, and filled over a fire pit of burning straw on the riverbank, with a basket of reeds under it on four ropes, and a tether of plaited palm fibre two hundred feet long staked into the ground. It had taken three tries to get it up. The second time it had caught fire and come down in the river. Now it hung above the camp in the hot morning, swaying, and John stood in the basket with Achillas's best signaller, a boy from Canopus with a set of coloured flags, and looked down at the third cataract the way the painted man on the wall in the Sphinx had looked down at the Nile.
The ridge was black with men. Ten thousand. Fifteen. Kushite archers in the front ranks, the famous ones, the bowmen Egyptians had called pupil-smiters for two thousand years, because they could put an arrow in a man's eye at a hundred paces. Behind them spearmen. On the wings, cavalry, on small fast horses. And in the middle, on a litter carried by twenty men under a canopy of red, a woman, very large, in a gold headdress, not moving.
He could see all of it. Every rank. Every gully in the ridge, every place where a man could hide. He could see a body of horsemen tucked in a wadi on the far left, waiting to come round the flank, that Achillas's scouts on the ground had walked right past.
The boy with the flags was being sick over the side of the basket.
"Left," said John. "Red and white. Cavalry in the wadi. Three hundred."
The boy wiped his mouth and waved the flags.
* * *
It wasn't like Carthage. He'd had a hand in Carthage. This he only watched.
The river boats went up first, against the current, rowing hard below the rapids where the water was still deep enough, and turned broadside to the ridge, and the bronze tubes in their bows fired.
He'd never seen guns fired in anger from above. In France he'd only ever been in front of them, or under them. From two hundred feet, in the balloon, over the roar of the cataract, the sound of forty bronze tubes going off together was small and flat, like a door slammed in another house. Forty puffs of white smoke rolling out over the water. And then on the ridge, a heartbeat later, forty places where the ranks of Kushite archers were suddenly not ranks any more.
Most of the tubes fired stones. Some fired jars. Clay jars packed with powder and iron nails and a burning fuse, that burst in the air over the archers' heads. He'd drawn those too.
The Kushites didn't run.
That was what he remembered, afterwards. They'd never seen anything like it in their lives, they'd never seen anything like it in two thousand years of fighting Egypt, and the archers stood on the ridge in the smoke with their dead around them and shot back. Arrows came over the water in clouds and fell on the boats and on Achillas's men forming up on the bank. The tubes fired again. And again. Two of them burst, on the boats, and John saw the white flash and the men flung in the river, and couldn't do anything but tell the boy which flag.
The cavalry came round the flank from the wadi, exactly where he'd seen it, and ran straight into the three thousand men Achillas had put there because of the red and white flags, and broke on their spears.
At noon the Kandake's litter turned and went back over the ridge. At the first hour of the afternoon the Kushite army went after it, still in order, still shooting, carrying its wounded. They left four thousand dead on the ridge.
Egypt lost nine hundred. Two hundred of them to its own guns.
* * *
He came down out of the balloon in the evening, when they let the fire under it go out, and walked up the ridge in the smoke and the smell, among the dead.
The archers had fallen in rows where they stood. Some of the rows had been cut in half by the stone shot, and some had no marks on them at all, killed by the nails from the jars. Their bows lay beside them, long bows of acacia wood as tall as a man, and their quivers, and their little bags of food. Dates. Bread. A doll made of rags, in one of them, that some man had been carrying for his daughter.
He stood there with the doll in his hand for a long time.
Cleopatra found him there at dusk. She'd been on the boats all day, on the river, under the arrows, in a bronze helmet that Achillas had begged her not to take off, and there was a bandage on her forearm where an arrow had grazed it.
She stood beside him and looked at the rows.
"I've never seen warfare like this," she said at last, very quietly. "No one has. The guns, the balloon. You up in the sky telling Achillas where every man was." She looked at him. "It's as if you'd brought it with you from a future that hasn't come yet."
"In a way," said John, "I have."
"Is it like this there?"
"Worse."
She was quiet. Then she took the rag doll out of his hand, gently, and looked at it, and put it back in the dead man's bag, and closed the bag.
"I'll send to the Kandake," she said. "Tomorrow. Not to tell her she's beaten. She knows that. To say that the river is one river now, from the sea to Meroe, under one crown, and that she can keep hers if she bows to it. Egypt's garrisons on every cataract. Tribute every flood. And in return, water lifts in Meroe, and engineers, and salt and honey, and her people can trade at Elephantine without paying the tax my father charged." She looked at the rows. "And the guns stay in Egypt. The next queen of Kush who thinks of crossing the first cataract can come and look at them."
"She'll take it."
"I know." She put her hand in his. "Come down. You're cold. You've been cold since Giza."
* * *
He tried that night, in the tent, when she was asleep.
He didn't know why. He lay on the camp bed in the dark with the roar of the cataract outside, and the smell of the ridge still in his nose, and the mask in its bag by his head, and he thought he'd just look at something. The lamp. The flame. Slow it a little, the way he'd done in Florence, with Leonardo's plumb weight. Four counts of Ave.
He pushed.
Nothing happened.
He pushed harder. The flame went on flickering at its own speed. It was like trying to lift a weight with an arm that had gone to sleep. He could feel the Hold there, somewhere, a long way down, but he couldn't get hold of it. He pushed until his head ached and his nose started to bleed, and the flame flickered, and flickered, and at last, very briefly, stood still for one count.
One.
He'd had fifteen in Kokura, without the mask, under the cherry tree.
He lay in the dark with the blood running into his mouth, and reached out, and his hand found the bag by his head, and he took the mask out, and held it. He didn't put it on.
He lay there for a long time, holding it, listening to Cleopatra breathe and the river roaring down over the rocks.
The hundredth time, Musashi had said, you won't want to take it off at all.
He'd lost count somewhere around Carthage.