‘Yeah.’ The MEK’s base in Iraq, known as Camp Ashraf, held thousands of Iranian exiles, including women and children – not just would-be soldiers. Until 2009 it had been guarded by coalition troops, but since Iraq had assumed responsibility for the camp the situation there had become far more precarious. Pro-Tehran factions in Baghdad were constantly trying to deport the occupants back to Iran – and if international pressure precluded shipping people straight into Iranian prisons, the same factions could still do their best to make the camp’s continued existence untenable. The MEK leadership certainly had a bloody history, and it was hard to know whether their renunciation of their old methods was sincere, but the whole community deserved something better than this desert limbo.

Nasim put her plate aside and curled up on the sofa beside her mother. It had been hard enough for the two of them, living illegally in Syria for three years, waiting for the UN to classify them as refugees and find a country willing to take them. They’d been cooped up in Damascus, in verminous apartments in the poorest neighbourhoods, sweltering in summer, freezing in winter. Their lives had revolved around evading the authorities, always having to move, or having to find the money to pay bribes to avoid being imprisoned or deported. Some schools had been willing to turn a blind eye to Nasim’s status, but that had generally proved both risky and expensive, so most of her lessons had been at home. Sometimes her mother had found back-alley jobs sewing clothes, and Nasim had stood beside her sewing machine, passing her pieces of material; at the end of the shift their ears would be ringing so loudly that they couldn’t hear each other speak. But she still met people who assumed that they’d simply jumped on a plane from Tehran to New York, where the mere mention of her dissident father had seen them naturalised on the spot, complete with bouquets and brass bands.

On the day they’d left Tehran, she’d wept twice as hard as on the day they’d hanged her father – because even after his death, she had felt she was abandoning him. She’d wanted to stay and fight, wanted to spit in the faces of his killers. That had been a meaningless, childish vision – and she would never forgive herself for the brutal accusations of cowardice she’d flung at her mother as she’d packed their suitcases – but even now, she couldn’t simply cast those emotions aside.

She knew that above all else, her father would have wanted the two of them to escape the shadow of the ayatollahs, to find a safe home, to flourish. But she doubted that she’d ever stop feeling that she owed him something more.

On the fifth day of the siege of Evin Prison, just before dawn, saboteurs got in among the protesters long enough to burn down the chemical toilets. Surveying the resulting black-edged sculptures in melted plastic, Martin wondered if the end had finally come. People couldn’t live like animals.

Within hours, though, shovels had been smuggled in from the surrounding suburbs and deep pits had been dug. Tents were commandeered, privacy was secured. By the time Martin confronted the inevitable and entered one of the reeking enclosures himself, the facilities were not just well-tested but adorned with graffiti, including some slyly vernacular English: ‘We honour Hassan Jabari for proving that a cock-up is better than a conspiracy.’

Evin Prison sat on the line where the northern suburbs of Tehran gave way, abruptly, to the Alborz Mountains, some twelve kilometres from the city centre. One minute there were crowded expressways, upmarket shopping malls and tiered apartment blocks in glittering white, the next there was barren rock sloping up into the mountains. Popular hiking trails began nearby, and a ski-lift wasn’t far away, though it was definitely not the skiing season. At the bottom of the rocky slope sat the prison, its high grey walls topped with razor-wire, watchtowers rising from the cell blocks. To the west lay a shady green park with a teahouse and restaurant; those facilities were closed now, but the park itself had proved invaluable, with the trees offering shelter from the sun, and now the soft, excavatable ground saving the assembled masses from complete indignity.

Protesters surrounded the prison on all sides, but the bare rock behind it had proved the hardest to defend. For three nights running, the police had used water-cannon to force a retreat back down the slopes. But they always ran out of water eventually, or their pumps ran out of fuel, and during the day the protesters rebuilt their barricades of metal drums and barbed-wire, and by sheer force of numbers pushed them up the mountain, driving back the police lines. Martin had watched from below as tear-gas grenades were smothered in drums of water or wrapped in fire-blankets, but never lobbed back to their senders. Apart from the sheer frustration of not prevailing, the police were offered no provocation: no stone-throwing, no swearing, no taunts.

The battles being waged in the suburbs around the prison were more complex, and it was hard to catch more than a few glimpses of the ebb and flow of territory, but the fact that supplies were still getting through demonstrated that the police had yet to form an impenetrable cordon between the protesters and their supporters. The authorities had cut off water to the drinking fountains in the park, but bottled water and a remarkable variety of home-cooked food were still finding their way in.

The prison itself was closed off now, but on the first day the guards had been only too willing to come out and interact. A line of protesters had stood at the main gate, and when ordered by a belligerent, near-hysterical officer to disperse, the first in line had replied, ‘My son is in your prison. He has committed no crime. I respectfully request that you release him now, or arrest me.’ IR links had ferried the man’s words from a phone in his shirt pocket all the way to a PA system in the park, and from there they’d blared out across the expressway.

When he’d been arrested, the next protester had stepped forward. ‘My sister is in your prison. She has committed no crime. I respectfully request that you release her now, or arrest me.’

The ritual had gone on for close to four hours; Martin had counted seventy-six arrests. Then, in the middle of the afternoon, the intake had ceased and the guards had withdrawn behind the gate. Either the beast had literally filled its belly, or someone in authority had decided that they’d made a mistake to play along at all.

Four days later, and still nobody knew what had befallen those seventy-six people. Rumours were rife, but Martin did not believe the worst: after surrendering themselves into custody, they would not have been lined up against a wall and shot. But the emergency decrees had eroded the already shaky protections of the legal system, and there’d be a strong temptation to portray the relatives of the dissidents caught up in the sweep as something far more sinister than anguished parents and siblings. Self-confessed spies and saboteurs would do nicely, and in Evin confessions generally came with bruises, or worse. With officials under stress and arguing among themselves, there’d be a perilous volatility added to the usual brutal machinery.

In the male ablutions tent beside the latrines there was a hefty pile of water bottles, but they were outnumbered by empties waiting to be refilled. Martin poured a little water into a basin, washed his hands thoroughly with soap, wiped some of the grime from his face and neck, then emptied the basin onto the ground outside. He itched to do more – literally, in places – but it was almost time for the noon prayers, which would put a big dent in the supply; it would have been selfish to make himself vastly cleaner than his own beliefs required.