Ferron produced other bits of evidence, selected bits of scholarship fed to Colon. 'There's really quite a conspiracy, it seems, to pour this nonsense of westward voyages into Colon's head. And it can't be a coincidence that your destruction of God's engines happened to occur on the very day that Colon's brother Bartolomeo was there to see it.'

Geoffrey was depressed at how much Ferron knew. Piously cruel he might be, but Ferron was evidently no fool. He tried to protest. 'What on earth can this wretched English girl have to do with the goings-on at the royal court of Spain? She's spent most of her adult life in York, locked up in the cell of an anchoress!'

Ferron said smoothly, 'That's what we're here to find out. Now you are put to the question, Agnes Wooler. Unburden your soul. I want you to tell me first the names of your co-conspirators. And when you are cleansed of that, we can move on to the detail of your further sins.'

Agnes, shaking, raised her upper body so she was kneeling before Ferron. She would not reply.

One of Ferron's aides whispered in his ear. Ferron nodded. 'That's enough time.' But before he proceeded, he hesitated. He said to Geoffrey, 'We are not monsters, Geoffrey Cotesford, whatever you English think of us. Hardened by the war against the Muslims we may be, but we are civilised, and pious in all things. And there is a process I must now follow, laid down by the Grand Inquisitor and sanctioned by the monarchs: a process tested in the law and the eyes of God. A process of five steps, at any of which a penitent may turn back to God and spare herself further suffering.'

Geoffrey said nothing.

Ferron turned to Agnes. 'You refuse to speak, Agnes Wooler. You understand that if you do not cooperate, further proceedings will follow.' After waiting for Agnes to respond Ferron nodded to a clerk, who made a cross in a book. Evidently that warning was the first step of the process.

Ferron stood. 'Bring her,' he snapped to the brothers, and he led the way out of the room. The brothers took Agnes's arms, hauled her to her feet, and dragged her after the others.

The room was suddenly empty, save for Geoffrey. He stood, his heart hammering, and he hurried out of the room after the rest.

They walked along a short corridor, lined with little offices inside which more churchmen laboured at mounds of paperwork. Geoffrey was reminded again that the Inquisition was a marvel of bureaucracy as well as cruelty. None of the clerks looked up from their work as the English girl was dragged past.

They came to a spiral staircase, its steps worn stone slabs, and down it they went, down into the deeper dark. At the foot of the stair they came to another room, bigger but no more brightly lit than the court office above. There was no furniture here, but the room was dominated by two pieces of equipment: a table fitted with leather straps and a kind of winch, and an odd arrangement like a ladder tilted up on trestles, around which stood buckets of water.

Geoffrey noticed mundane details. Channels cut in the floor, leading to drains. A thick oaken door that looked impervious to noise. He felt very cold.

Agnes was made to stand before the table device. A soldier's gloved hand under her chin ensured she saw it.

'Step two,' Ferron said. 'Agnes Wooler, you are being shown these instruments of God's mercy. Do you understand what they are? Repent now and spare yourself this righteous pain.'

Agnes stared dully, but said nothing.

The clerk made another cross in his book, and Ferron said, 'Step three.'

One of the brothers closed his huge fist at the neck of Agnes's shift, and pulled. The filthy cloth ripped easily, and she was left naked, surrounded by men, in the middle of the cold room. She hunched her shoulders against the cold, but did not try to cover herself. Geoffrey knew she was nearly thirty years old, but she was so emaciated she looked like a child, her ribs showing, her legs like saplings. The flesh between her legs was stained with piss, shit and blood, and her back was marked with bloody weals. The brothers leered at her shrivelled dugs, the patch of auburn hair between her legs.

Again Ferron asked her to confess. When she did not speak, Ferron said, 'The fourth step.'

The brothers grabbed her and pushed her onto the table. They took hold of her wrists and ankles, pulled them back so her arms and legs were stretched, and fixed her in place with tight bonds of metal and leather. Agnes did not resist. One brother went to the winch at the top of the table. He tugged it experimentally; the table creaked, and the mechanism under it, a mesh of gears and levers, shuddered as if eager.

Agnes lay passively, her body a white strip of fragile flesh laid over wood and iron.

Ferron stood over her. 'Have pity on yourself, child,' he said. 'You were an anchoress. You don't deserve this. Just tell me the truth.'

She whispered, 'I know only one truth. That my father's love doomed me to this.'

Ferron frowned, clearly wondering what new heresy this was. But Geoffrey knew that the father she spoke of wasn't God.

Ferron ran out of patience. He glanced at the brother at the winch, who spat on his hands.

'Step five.'

The brother hauled. As gears bit and ropes tightened, the wooden tabletop lengthened, creaking. Agnes screamed, the noise huge in the confined room.

But still she would not speak. Ferron ordered the winch turned again, and then again.

Geoffrey forced himself to watch. He heard a ripping, cracking sound. Agnes's knees and elbows turned red and lumpy, and her shoulders were oddly twisted. Of course it would be the joints that would fail first, he thought helplessly, not the bones.

Still she did not talk.

Ferron made a curt gesture. 'Enough. Keep her conscious. We'll try the water.'

The brother at the head of the table released a latch, and let the winch spin loose. The brothers removed the buckles and clasps. Agnes didn't move. One brother slid his arms underneath her and lifted her. When her knees bent and her arms fell forward she was convulsed, and her screams became bestial.

But she was lowered onto the tilted ladder, with her head above her feet. Again she was strapped in place. Her head was pinned down by a metal band around her forehead. Twigs were forced into her nostrils, coated with fat so they plugged her nose.

Guards stood by, one holding a cloth and a bit of metal, the other a bucket of water.

Ferron leaned over Agnes. 'Can you hear me, Agnes? God doesn't want to see you suffer. If you choose to confess, after it begins, then all you have to do is look at me, as you are now. Do you understand? Is there anything you wish to say to me now?'

'He called me his Agnes,' she whispered. 'His precious Agnes. I was no Agnes when he was done with me…'

Geoffrey's heart broke a little more.

Ferron, baffled, irritated, turned away. 'Do it,' he snapped to the brothers.

The one with the cloth stepped up. With casual, brutal strength he grabbed Agnes's cheeks, forced her jaws open and pushed his metal frame through her lips. It was like a funnel, Geoffrey saw, that kept the mouth wide open. Now the brother laid the centre of his cloth over the funnel and stepped back.

Agnes was still, save for her eyes, which flickered back and forth over distorted cheeks.

The other brother stepped up with his bucket of water. With care, he poured a bit of water onto the cloth. The water's weight forced the cloth into Agnes's mouth. The brother kept pouring, and Geoffrey saw that the cloth was drawn deeper into Agnes's throat. At last she swallowed, convulsively, and she coughed and choked, but she could not get the cloth out of her throat. Still the brother poured, and again she gagged, each swallow drawing the cloth deeper down her throat. Soon Geoffrey saw that she was close to panic, her battered body fighting back, immersed in a fear of drowning, of suffocating.