The rotation held.
Turn A. Turn B. Turn A again. The rhythm of it became its own kind of breathing, a pulse the whole car moved to, and they kept it going through the full body of the second hour while the desert around them lightened from grey into the pale gold of proper morning and the sun came up over the eastern edge of the world without asking anyone's permission.
Mayo was the only one not in the rotation. He had no place in it, no role, nothing his hands could do. So he watched them instead.
He watched Ozair's face, which was running with sweat, jaw set, doing his part in every single turn without exception because Toviro had put him in both rotations and Ozair hadn't complained once since it began.
He watched Aryan, whose breathing had become shallow and deliberate in the way of someone managing effort they cannot afford to waste.
He watched Elina timing her bursts with precise economy, not a drop of force more than the five seconds required.
He watched Mina rotating her shield between the tires with her eyes on the road, her knuckles pale, her face holding a steadiness that cost her more than it showed.
He watched all of them and he kept his voice even and his face steady.
"One hour down," he said. "Just two more. You're doing it. Keep going."
It was the only thing he could give them so he gave it cleanly, without apology.
"Turn B," Toviro said, breathing visibly between words.
Ozair's hands came up again. The sand channel extended ahead of them, a thin, continuous sheet, and the car held its pace.
Another minute. Then another.
"Turn A."
They switched. The water sat at five hundred metres behind them. Sometimes six hundred. Never less than three hundred.
The rotation was working the way Toviro had designed it to work, spending just enough and never more than that.
An hour and a half.
The sweat on Ozair's jacket had soaked through the collar and across his shoulders, and at some point during Turn B his hands came down not because he chose to lower them but because his arms simply stopped holding them up.
He tried to lift them again and couldn't. He sat there with them in his lap, breathing with the urgency of a body beginning to give in.
Elina grabbed his arm. "Ozair."
He looked at her. He tried to say something and it came out as breath.
"Water," he said finally.
Elina didn't hesitate. During the brief window of Turn A while she was resting she turned and climbed up onto her knees and reached over the back of the third row seat into the supplies section.
She found a carton of water bottles, pulled it forward, and took three from it.
She opened one and brought it to Ozair's mouth and tilted it, and he drank with his eyes closed.
Then the car shifted.
A subtle change in the angle of the floor beneath them, so gradual at first that it felt like imagination, but it persisted and grew.
The engine note changed.
The road was tilting upward.
Elina sat down and looked at the windshield.
They were climbing.
"What is this?" she said.
"The road's going up," Mayo said, watching through the windshield. "Like a mountain road. We're ascending."
She didn't waste the moment. She grabbed two more bottles and threw them sideways to Mayo, who caught them and immediately turned and opened the first one and brought it to Toviro's mouth from the front seat, then held the second up for Mina.
Mina drank without taking her eyes from the road for more than a second.
Elina opened her own bottle and held it to Aryan's mouth at the door, and he drank, and then she drank herself, one long pull, and put the bottle down.
"We need more force on the climb," Toviro said. His voice was dry but clear. "The car will lose speed going up."
"What mountains are these?" Mayo asked.
Mina looked at the road rising ahead of them, at the shapes of the terrain, at the way the cliff faces curved. Something in her expression recognised it.
"Mahi-Parr," she said. "These are the mountains of Mahi-Parr."
"And the roads?"
"No one ever came here. The roads were built and then forgotten." She kept driving. "They go up and down and zigzag the whole way through."
Toviro's eyes moved forward. "One hour left. These roads will help us. The mountain will give us angles the water can't follow cleanly." He paused. "Keep going."
Mayo turned to look out the back window.
What he saw stopped his breath.
The water wasn't distant anymore.
The wave behind them had grown, swollen by everything it had consumed across the desert behind them, and its crest now rose higher than the hillsides flanking the road.
It moved through the land the way a tide moves through a harbour, steadily and without exception, and its face was dark and absolute.
"It's coming faster," he said. "The climb is slowing us down. Go, Mom. As fast as it'll take."
Mina's hand found the small secondary gear selector beside the main one. Mountain driving. She engaged it, and the rear tyres bit differently into the road surface, the car's weight redistributing, the climb becoming possible where it had been threatening to become impossible.
The speed dropped but the grip held.
The water arrived at the base of the mountain slope below them.
It didn't slow down.
Mayo pressed himself toward the back seat. "It's coming up. It's coming up the mountain."
"Everyone hold something," Aryan said.
They reached the crest. The road levelled for fifty metres, just enough to breathe, then the descent opened ahead of them.
Mina pressed hard and the car surged forward.
A steep, narrow road going down the far side of the mountain range, badly maintained, cracked in long lateral fractures, the edge on the right side dropping away into nothing.
The water crested the mountain behind them.
"Turn the engine off," Toviro said.
"What?" Mina looked at him.
"Off. Now. Let it go."
She turned the key.
The engine cut. The silence was immediate and huge. And then gravity took the car.
It moved down the mountain road on its own weight, picking up speed faster than the engine had managed on the climb, the road rushing up underneath them, the cracked tarmac hitting the undercarriage in rapid jolts that threw everyone upward in their seats.
Aryan grabbed the headrest. Mayo grabbed the seat. The car swung toward the edge of the road on a curve and Elina made a sound she didn't choose to make.
Toviro put his staff out of the window.
The tip pressed against the cliff face on the left side and a rigid barrier extended outward from the tip, an angled surface that caught the car's momentum and redirected it back toward the center of the road, correcting the angle, the car bouncing hard but staying on the tarmac and not the edge.
Another curve. Toviro adjusted the staff. The barrier reappeared on the other side. The car corrected again.
They were moving faster than the car had any business moving on a road like this, but they were moving, and behind them the water was pouring over the mountain crest and coming down after them and it was faster than all of it.
The tunnel appeared in the cliff face ahead without warning.
The entrance came up in the headlights and Mina turned the key back one click to restore power and the lights blazed on and the car went in.
Dark. The sound of the engine and the tires and the frame bouncing filled the enclosed space at enormous volume.
The tunnel ceiling was low. The walls were close. The lights lit a hundred metres ahead and no more.
Then light at the far end.
They came out the other side into open air and morning light and Mayo turned and looked back.
The tunnel entrance held for two seconds. Then the mountain above it moved.
A section of cliff, weakened at its base by the water coming over it, broke away in a slow, enormous fall and came down across the tunnel mouth.
The water that had been following them through it hit the blockage and the force of the impact sent it sideways, through the cliff's own fractures, through every weakness in the rock face, emerging in half a dozen new channels at once, white and violent and loud enough to feel in the chest.
They were out the other side and the mountain was coming apart behind them.
Nobody spoke.
They were high on the far side of the range now, and from up here they could see.
They could all see.
In every direction behind them, as far as the eye reached, there was water.
The desert they had crossed was gone. The flat land of Wakhan was gone. The mountains they had just driven through were going.
The water hadn't merely followed them. It had taken everything, every last piece of land behind them, swallowing it with the patience of something that had been given all the time there was and intended to use it.
The wave crests caught the morning sun and threw it back in long, cold flashes.
The mountains of Mahi-Parr were sinking.
Entire peaks were disappearing beneath it.
No one said anything. The scale of it was past the language available to them.
Aryan, who had survived things and processed things that most people never encountered, sat in his seat and looked at the water swallowing a mountain range and found nothing to say.
It was Aryan who eventually spoke, and what he said was: "Who built these roads."
His voice was rough, stripped to almost nothing by two hours of effort. It was barely audible above the wind.
Mina understood what he was doing. She understood immediately.
"Nobody came here," she said. Her voice came back clearly. "The mountains of Mahi-Parr had no population. The roads were built once, for a reason nobody remembers, and then left."
She kept her eyes on the descending road ahead. "That's why the condition is what it is."
Aryan nodded.
The car kept moving.
They came down off the mountains in the next half hour.
Toviro held the barrier out the window on every curve and the car stayed on the road through all of them, barely, never comfortably, but each time the barrier found the tarmac and kept them on it.
On one descent the car left the road entirely for two seconds and came back down with a crash that bent something in the undercarriage and made a sound that none of them wanted to think about, but the wheels were still turning when it landed.
The road flattened.
The mountains ended and the terrain became something different again. Dry, cracked earth.
No sand, no vegetation, no structures of any kind.
The road surface here was better, the kind found in low, flat places that saw less movement and less erosion, and Mina brought the engine back to full power and the car straightened.
Mayo turned and looked behind them for the last time.
The mountain range wasn't there anymore.
The water had taken it. The whole range, the peaks, the cliffs, the roads they had driven, the tunnel, all of it was beneath the surface now.
The wave came down off where the mountains had been and moved toward them across the flat land, and it was moving faster now because the mountains were no longer there to break it.
It had followed them to the last piece of land in the world.
And ahead of them, there was nothing left but the ocean.