The filter worked.
The water came through slowly at first — single drops, the colour of old brass — and then, as the filling materials absorbed their first saturation, it found its rhythm. By the time the lower bag had been running for ten minutes, the flow from its base was nearly continuous: a thin, bright, completely clear line falling into the copper bath below.
Aggo was lying on his stomach underneath it with his face tilted up, watching.
"It's clean," he said, with the hushed reverence of a man watching a miracle perform itself. "It's cleaner than the river water."
Jorah crouched beside the bath and cupped a handful. He looked at it for a moment. He smelled it. He tasted it carefully, with the expression of a man prepared to be wrong.
He was not wrong.
He stood up and looked at Daenerys with an expression that she was coming to recognise — the expression of a man whose previous estimate of something has just been revised upward and who is recalibrating in real time.
"The waste is full of shallow pools," he said. "Mudflats. Every dried riverbed has at least a few. The problem was never the quantity — it was the quality." He was already thinking ahead, she could see it. "If we break this bath down and recast the copper into a dozen smaller kettles — one to every scout-pair — they can range thirty miles ahead of us, filter as they go, leave caches for when the column arrives."
She looked at him. "That's a good idea."
He looked slightly surprised, which made her wonder what he had been expecting her to say.
"Do it," she said. "Have Aggo pick the pairs. I want them moving before the column does each evening."
The filter clogged for the first time an hour later.
Rakharo had been tending it, pouring contaminated water into the top bag at a steady pace, and he came to her with the expression of a man reporting a problem he does not yet understand.
She went to look. The top bag was full of standing water that was not moving. She pulled the corner back.
The smell arrived before the sight did. She took three involuntary steps backward.
The red-orange sand inside the bag had acquired a coating of dense black-grey sludge — every particle the water had been carrying, deposited in a compact layer across the filter medium. The system had done its job so well that it had filled its own working capacity.
"Change the sand," she said, from a safe distance. "And the charcoal. The cotton can be rinsed and reused, but the sand and charcoal need to be replaced every few hours."
"Replace them with what?" Rakharo asked.
"Riverbed sand is everywhere. For charcoal — " she looked at the dead grass growing in the rock cracks nearby — "pull the devil grass. Pack it tight, chew it first to break the fibres if you need to."
Afanti made a sound.
"Ask the mares," she added, before he could object. "The ones with good temperaments. Not the stallions."
She approved the idea of boiling everything after filtering and added salt and dried figs to each batch before distribution. The combination — faintly salty, faintly sweet, still warm — was received by the camp with the enthusiasm of people who had been moving through a furnace for three days. Doreah declared it the best thing she had ever tasted, which was probably heatstroke talking, but the sentiment was genuine.
The third camp was eighty miles south.
They had stopped at a wide, shallow mudflat that held enough contaminated water to run the filters through the night, and in the pre-dawn quiet Daenerys watched the construction of a curved low wall from loose rock and dried mud — not structural, not defensive, just positioned to block the sun's direct angle once it cleared the eastern hills. By mid-morning it had reduced the campsite's effective temperature by what felt like ten degrees. By the afternoon it would be insufficient again, but they would be moving by then.
Small gains. Accumulated.
On the third morning, she addressed the hair problem.
She had been thinking about it since the first day of travel, which was how long she had been aware of the specific quality of the smell that rose from her riders when the wind was wrong. The Dothraki did not wash often at the best of times. Three days of hard marching in extreme heat without adequate water, and the situation had developed its own character.
She found Aggo before he had put his riding vest on and stated her intention directly.
His head began moving before she finished the sentence. "If I cut my braid, every rider we meet will know I was defeated. Or enslaved."
"I'm not touching your braid," she said. "The sides. The crown. Everything except the braid itself."
"That will look—"
"Terrible," she agreed. "But you'll be cooler by ten degrees and you'll stop growing what is currently living in your hair."
"What is living in my hair?"
"You don't want to know."
She looked at Jorah, who had been following this exchange with the expression of a man who would like to offer assistance but is aware that he has approximately four strands of hair and the problem does not apply to him.
"Find a sharp blade," she said.
She held the lamp. Jorah did the shaving.
The dagger moved through Aggo's hair the way a blade moves through something that has partially solidified — not quite flesh, not quite felt, something in between. Each pass revealed pale skin beneath a layer of dark crust that had accumulated over months of dust and sweat and heat and the particular biology of a man who had never considered that hair required maintenance.
"Don't breathe through your nose," Daenerys advised him, from two feet back.
"Too late," Jorah said.
Rakharo was watching from the tent entrance, his expression moving between scientific curiosity and something approaching horror.
When the last of the side hair came away, Aggo sat very still for a moment. He raised one hand and touched the bare skin of his scalp. He touched the braid, intact, hanging from the back of his head, undisturbed.
"How do you feel?" Rakharo asked.
Aggo's expression shifted through several configurations before settling on one that Daenerys could only interpret as a man emerging from a long and difficult experience into unexpected relief.
"Like taking off," he said slowly, "a sheepskin that has been sitting in the sun all day." He touched his scalp again. "But not an illusion. There is genuinely less weight."
"Two pounds at minimum," Daenerys said.
"The braid is untouched," Quaro said, from the back of the group. He had been looking at Aggo's head with the focused attention of someone solving a problem. He looked at it from the left side, then the right. "The braid is completely intact. Nothing about the length or the bells has changed." He looked at Daenerys with an expression of rising certainty. "This is a gift from the horse god," he announced. "Brought to us through the Khaleesi. This style should spread across every khalasar in the Dothraki Sea."
Daenerys opened her mouth. Closed it.
"I want it," Jhiqui said, from the serving women's side of the camp.
"You will have short hair," Daenerys told her. "All the women will have short hair."
"But I want the men's style," Jhiqui said.
"Why?"
"It looks powerful."
Daenerys looked at Jhiqui. Looked at Aggo's head. Looked back at Jhiqui.
"Short hair," she said firmly. "We're moving at dusk."
By the time the column formed up that evening, every male rider had the new cut — sides shaved, braid untouched, the crown scraped clean. The transformation had moved through the camp with the speed of something people had been wanting permission for. Jorah had spent most of the afternoon with a dagger.
The serving women had Daenerys's bob cut, in the end — a clean line at the jaw, practical, cool. Several of them had started toward the blade themselves before the men were finished.
Daenerys kept her silver hair. She was the only one.
She did not need to cut it. She had her own method of keeping it clean, which involved walking into the cooking fire when no one was looking and standing there until everything that should not be alive in her hair was no longer alive. The three dragons came with her every time, fluttering around her shoulders and feet, small enough still to fit entirely in the fire's light — their wings translucent against the orange, their scales beginning to catch and throw back the heat with an intensity that was no longer just warm.
She was learning, from these fire-baths, what they needed to eat.