Tiziri.

The wadi of Ghardaïa is dry almost all year. It's a wide gully of pale stone that cuts through the lower part of the city, and people walk across it like just another street. Then, some year or other, it comes down full.

Tiziri was six the first time. Her mother took her and her sister out into the street still in their nightclothes, and the whole city was out too, standing at the edges, watching the water break against the dikes. Down in the valley, the flood gets split by canals and sluice gates until every orchard in the palm grove gets the share that's owed it. The allocation has been settled for centuries, and it's carried out in full view of everyone, with witnesses, arguing over the height of a stone if it comes to that. In a place where it rains like this, water is the one thing that's managed in public.

What she kept from that night is the noise: a low, thick rumble that reached her through her feet before it reached her ears, and that kept sounding even after they'd been brought back inside and the light switched off.

There were four of them in two rooms. Tafsut, the mother, raised them alone, sewing on commission and cleaning at the school, and she tells it like this: that Tanina, the eldest, changed the little ones while she finished a hem. Tiziri slept against the wall. She says the wall used to hum.

Tanina left for Ouargla before Tiziri started working, and she still calls on Sunday afternoons. She's always the one who calls. Ten minutes, and they both hang up at the same time.

One night her mother sent her into the palm grove to find Massin, who'd gone off to play and lost track of time. Tiziri went down without a flashlight, stopped where the irrigation channels start, turned her head once, and walked straight toward a wall at the far end. Massin was behind it, sitting down, eating fallen dates. She didn't call his name a single time.

The two of them walked back, and her mother went on sewing. That was that.

Idir, the father, always lived apart. He has an orchard down in the palm grove and spent many years in construction. Tiziri has seen him seven or eight times.

Among her people, that's handled differently. Fathers don't keep a house; houses belong to the mother, and between one house and the next there can be a day's walk. Her people are spread out enough that the custom is to know roughly where everyone is and to manage not to cross paths. When two of them do meet at night in the same spot, one changes direction and the other keeps going.

Nobody has ever counted them. They show up on the list of peoples that are doing fine, and that sits quite comfortably alongside the fact that years can go by without an outsider running into a single one of them. For three decades, on the western side, almost no word came from anyone. Nobody vanished — people simply stopped being seen. The village draws a clear line between those two things.

Idir asks about her whenever someone heads down to the palm grove, and she asks about him whenever someone comes up. The only strange part is that she knows the exact number.

She left school at seventeen and spent a stretch behind the counter of a spare-parts shop. She got into the water utility because of a sign taped to the agency door: they were hiring for the night shift.

The job comes down to this. An urban network loses water through old joints and stretches that have been buried for half a century, and a leak under the asphalt can take years to reach the surface — the ground just swallows it. To find it, you walk the sector on foot with a geophone, a contact microphone you set against the road, and you confirm it with a correlator, which puts a sensor on each side of the suspect stretch and works out the exact point from the time difference between the two signals. It's done at night for practical reasons: the city stops using water, the pressure in the network rises and the leak sounds louder; the streets empty out, the air conditioners shut off, the irrigation stops — and the background noise drops so much that the system can be heard on its own. Half the trade is getting everything else to shut up.

The reports are written in French. At home they speak tumzabt, and for Tiziri the hours come out in tumzabt and the pressure readings in French, so she jots it down first and translates after.

Almost nobody wanted the shift. She said yes on the same visit, before she'd even asked what it paid.

She was trained by Ammi Bakir, who'd spent half his life walking that network and didn't talk much. He taught her to tell a leak apart from a pipe that's simply working, to distrust the correlator on old asbestos-cement pipe, and to write up the report before starting the van, so she'd get home with a clear head. He also taught her to let the neighbors who come out in their pajamas asking what's going on have their say — that's half a night's work done right.

Before he left, he gave her a squared-paper sheet, folded, with the order the sectors get walked in, written out by hand. It starts at the corner by the old reservoir.

He died one March, his work overalls still in his locker. Tiziri kept the order then, and she keeps it now. The reservoir has been out of service for years, and the sector is much easier to enter from the other side — people have told her more than once — and she shrugs, and goes in the way she goes in. The sheet is still in the glovebox.

She goes out at eleven. She parks, cuts the engine, and waits inside until the chassis stops ticking before she opens the door. Then she crouches in the middle of the road, presses her open hand flat against the asphalt, and stays like that for a good while, saying nothing.

Her reflective vest is a size too big, her boots have zip ties instead of laces, and over everything she wears a sage-green wool coat that isn't regulation issue and that she puts on the moment she steps out of the van. Her flashlight hangs off her belt, switched off — she only turns it on to write. The passenger seat is torn and has been patched with the same tape for years, and the tape always catches her trouser leg at the same spot on the knee. It's still there.

The van also carries a regulation water jerrycan, which she returns full every week. She makes the same joke handing it over, and it always lands. She spends her nights chasing water that's escaping under the city, and she's never once been thirsty in her life.

Summer is hard on her. When it's hot, people water their gardens before dawn, the whole sector fills up with noise for her, and she gets less done and turns sharp with anyone who calls her on the radio. She blames it on consumption, which happens to be true as well. At the office, on the days she has to go in and sign off, she always sits with her back to the air conditioner and her chair pulled a little away from the desk. If someone's taken her spot, she stays standing.

They assigned her Ilyes for a three-month term. He was quick with the paperwork and asked a lot of questions.

In his second week he found a leak on a stretch of Market Street that she'd already walked that same week. He showed her, pleased with himself, the correlator still sitting on the ground. The unit's report goes out under the sector's name, not the technician's, so the find ended up where they all end up: under hers.

Ilyes asked once how the reports got signed. She told him it was by sector, which was true, and that wasn't the real reason. The following month he requested a transfer to the Metlili unit and left, saying goodbye only to the boss. He left behind his geophone, which is quite a bit better than the unit's own. Tiziri uses it every night. It still carries a scrap of tape with his name half worn away, and she hasn't taken it off, hasn't covered it up, and doesn't look at it.

A few years back she asked for the permanent night shift and the upper sector, the one that's most spread out and farthest from the depot. To justify it she wrote up a sheet about data continuity that she made up from start to finish. Nobody questioned it, and nobody's opened it since.

The sector boss sends her an apprentice a couple of times a year, and she always says yes. They come out of the three months filling in flawless reports. He's remarked on it once or twice, that it's odd none of them ever end up finding anything on their own, and he's settled for her explanation, which is a good one and usually starts with, "You just have to know this neighborhood on foot."

When people ask how she knows, she says she's walked this neighborhood inside out. When they push, she says the correlator lies on old asbestos-cement pipe. She says it calmly, and it sounds reasonable, because both things happen to be true. She marks the spot by hand, has them set up the equipment anyway, and the equipment proves her right within a foot.

She works alone, and her pulse stays steady. She lifts her head when someone comes up the street behind her, long before they turn the corner, and keeps her eyes fixed on the gap they're about to come through. The apprentices always enjoy telling that part afterward.

At the edge of the sector there's a patch of waste ground littered with rubble, with no pipe running through it. She stops there for a long minute every night, facing the waste ground, and then moves on. She's never explained it, and nobody asks twice anymore.

Aksil is a maintenance electrician at a bottling plant and lives in Berriane, up to the north. They met on a course about network pressure, in Ouargla, and they see each other on her days off, a couple of times a month. Neither of them calls that little. Among her people, couples keep separate houses, and it would never occur to anyone to ask when they're moving in together.

In January he said he was going to request a transfer to Ghardaïa. To the center, to a rented apartment, twenty minutes on foot from her place. Tiziri said fine, they'd see, and started clearing the table. Aksil hasn't brought it up again since February, and neither has she.

Her younger brother, Yuba, who still lives with their mother and starts and drops his studies every year, gets money from her every month. Tafsut doesn't know. If she found out, she'd think it was fine; Tiziri simply prefers that nobody know. When she stops by to drop something off at the house, she stays standing, and her mother has stopped offering her a chair.

At eleven she puts the geophone in her bag. The old tape catches her palm as she zips it shut. She starts the engine and drives to the corner by the reservoir, which is where the route begins.