There had been a river here a month before. A full-blooded river jolting over rocks, rippling with currents, swooshing around bank bends. Now there was no river. Just an arid depression, not even a hint of moisture to suggest that there had ever been water here.

‘Where is it?’ asked Alex.

His translator, William, a Nilote from the area, stood beside him, gazing at a bank which had been green when they’d first driven through shortly after Alex’s arrival in Saraaya. They were sixty kilometers north of town, here to survey one of the main grazing thoroughfares through which the nomads passed on their way south.

‘It’s gone,’ said William.

‘Gone?’

‘I guess it dried up already.’

‘And when will it come back?’

‘Next July maybe.’

‘Maybe?’

‘It used to come back every wet season, but the last few years, it’s so-so. Sometimes it comes, sometimes it doesn’t.’

Alex turned back to the landscape. A scene that overwhelmed and underwhelmed all at once with its spectacular monotony. Blank slate of a bleached sky. Flat land stretching around him. Clumps of desiccated trees to the east. In the far distance, a man sitting atop a camel wound his way from nowhere to nowhere. Alex had been sent to this remote district between north and south Sudan to update maps. It was an information-gathering project run by an American NGO based in the capital, Khartoum, nine hundred kilometers to the north. The maps in use by the local authorities were out of date – a new map was needed to help the organization tailor and deliver aid to the district. Alex had been hired from America to do the job. He’d landed in Saraaya at the turn of the new millennium to find hostilities between southern rebels and northern government simmering in the background.

After authorization for his map had finally arrived the week before, he had set about his work in earnest. Trailed by William, he’d zipped around the district with his measuring rope and his surveying telescope and his satellite devices, pouncing on unsuspecting passersby in the market to ask about farms and roads and grazing routes; traveling to villages and water wells and nomads’ camps in the plains on the peripheries of town. He and William had undertaken expeditions to the sandy plains of the goz to the north, which stretched from Chad to the White Nile. Great tracts of flat semi-desert unfurling as far as the eye could see, short, dry trees dotting the landscape here and there.

They had driven south, to the enormous wetland terrain of the Sudd, a carpet of marshes and swamps and bogs with islands of floating reeds as vast as football fields, feeding into the White Nile that flowed toward Khartoum. They had explored the network of rivers between these two terrains, life source of nomads and Nilotes, irrigating crops, nourishing livestock and people.

But the more Alex studied the landscape – squinting over his maps by night and gathering information during his expeditions by day – the more confused he became. He had never dealt with a geography like this before. It confounded everything he knew about natural habitats, land formations, water systems. He was used to landscapes changing slowly, in minuscule increments, over years of soil erosion, the weathering of rock layers, the creep of vegetation.

But here, from one season to the next, the landscape changed completely. During the rainy season swamps and rivers and lakes materialized, only to disappear entirely during the dry season and reappear in different places with the following rains. A river twenty meters wide that gushed with torrential water dwindled to a pathetic dribbling stream three months later, or dried up altogether, as this one had. Desert turned into lush, rolling grassland between May and November, only to turn back into desert during the dry season. Nomadic settlements sprung up with their rickety reed houses and cattle and camels in one place only to be packed up soon after. Even the town, Saraaya, was in a continuous state of upheaval. It had been destroyed three times during the war. Each time it was rebuilt – after people returned, dragging behind them their diminished belongings – things changed. Streets shifted. Families invaded each other’s compounds. Land which belonged to one person was suddenly farmed by someone else. The market disappeared, reduced to skeletal bones of burnt-out stalls, only to spring up elsewhere, with all the hustle and bustle of trade. Everything – villages and rivers and grazing routes – had two names, one in Arabic, and one in Nilotic, so that he found himself having to cope with the confusion not only of multiple languages, but also of multiple place names.

One map, he realized now, would not be enough. He had to make two. One depicting dry-season geography and one the wet-season landscape. Even then, he knew that within six or seven years the maps would again have to be updated. Once rivers shifted their courses the meander lines would have to be redrawn; new grazing routes would have to be shaded in, new swamps, new deserts spreading south with diminishing rains.

He had little time to finish the work – only four weeks to present something to his boss Greg, who’d been calling from Khartoum to check on his progress. Alex had started late. Authorization for the map had been held up by the troubles in the district. Southern rebels and the northern government were at each other’s throats in a war that had been ongoing since independence in ’56. And Saraaya, along with its oil fields, was right in the middle of it. Whoever controlled the district controlled the oil. Right now it was the government.

After his last phone call with Greg, in which his boss had exhorted him to get going quickly or else, Alex had asked William to arrange a meeting with Nilote and nomad elders. Three days later they’d arrived to find a large group collected in a clearing on the edge of town, under a tree whose branches were still verdant at the end of the rainy season. Men and women and children sat on straw mats on the grass. Light darted and leapt from face to face. Alex stood nervously before the unabashed gaze of the congregation, branches above him swaying with a breeze that stirred the heat into life rather than dispersed it.

He hadn’t expected so many people to show up. William had arranged for him to meet a handful of elders, but word had gotten out about the meeting, and he’d found bodies and faces packed under the shade, looking back at him expectantly. Being the only white man for miles around meant that he drew a crowd.

Turning to William, he said, ‘Can you ask them to introduce themselves first?’

One of the Nilote elders – a man with drooping eyelids and milky irises and wearing a red beret angled jauntily on his head – spoke. William translated. The elder wanted, first, to hear from Alex. What was America like? Did he like Saraaya?

The next ten minutes were lost to chitchat. Growing impatient, Alex told William to ask about the boundaries.

‘They will answer your questions, so you must show them the same courtesy.’

Alex felt the precariousness of the balance of power he shared with his translator, who was really the one in control of things, and he was compelled to oblige him by answering more questions from the crowd.

Finally they returned to the business at hand. William translated as Alex, pointing to a map pinned and fluttering against the tree, tried to explain what he wanted to know. An old woman in a blue dress yawned. Three children fidgeted at the front. A man in a jellabiah scratched his arm. A little girl sucked her thumb. He rushed on.

‘Tell them I’m meeting with them to determine the boundary between Nilote farms and nomad grazing lands,’ he said. ‘Ask if any elders would like to speak to the matter.’

William translated. The same Nilote elder rose, propping himself up on his stick. He pointed to the horizon. The boundary, he said, was clear. Since the time of his forefathers there had been an understanding that when the nomads arrived in Saraaya at the end of the rains each year, they could graze their cattle north of the bend of the River Kinu, at a village about one day’s walk from the town. Their grazing land stretched from that bend up to the gum-tree forest. The nomads who had lost their herds in the droughts and settled in Saraaya cultivated farmland in that stretch. Down from Saraaya to Agok was Nilote grazing land, and from Saraaya to the savannahs was Nilot farmland.

Murmurs of assent rippled through the crowd. But then a nomad elder stood up. The jellabiah he wore was a bright white, brighter than those worn by the men sitting with him, a turban wrapped neatly above a high brow and small eyes and a thick, graying mustache.

It’s true, he began, that back in the time of their forefathers, the nomads grazed north of the river bend. But that was long ago. Before the war. Before the droughts. Back in the time of the English. Things had changed since then. Grazing routes had shifted with lessening rains, war had scattered people. Many of the nomads had settled to farm, many of the Nilotes had moved south to join their kinsmen beyond the savannahs. The land boundaries were different now.

When he spoke again, there was an explosion of movement. People sprang to their feet. Babies crawling on the ground and little boys and girls hovering around the circle stopped what they were doing to stare at their agitated parents in surprise.

‘What did he say?’

‘He’s saying the nomads’ land stretches from Saraaya up to the gum-tree forest.’ William’s finger traveled from the black dot of the town on the map up to a gray-shaded area, about thirty kilometers north west, indicating the forest. ‘He’s claiming half the land the Nilotes say is theirs as grazing pasture for the nomads.’

Shoes and sticks rose in the air. Turbans unspooled to the ground. Heads and hands and legs were suddenly locked in a jumble. From the sidelines, women urged on their menfolk. William plunged into the circle to pull people apart. Alex too pushed his way in. Immediately someone’s elbow landed in his cheek, and he stumbled out, eyes watering from pain.

That was the first meeting. He arranged meetings with each group separately, but the map of nomad grazing routes then conflicted with the map of Nilote grazing routes.