When all the lamps were lit, Godwyn opened the big wooden door to the outside. The night air bit sharply at Gwenda’s ears and the tip of her nose. The overnight guests pulled their coats around them and began to shuffle out. When Sir Gerald and his family moved off, Pa and Ma fell into line behind them, and Gwenda and Philemon followed suit.

Philemon had done the stealing until now, but yesterday he had almost been caught, at Kingsbridge Market. He had palmed a small jar of expensive oil from the booth of an Italian merchant, then he had dropped the jar, so that everyone saw it. Mercifully, it had not broken when it hit the ground. He had been forced to pretend that he had accidentally knocked it off the stall.

Until recently Philemon had been small and unobtrusive, like Gwenda, but in the last year he had grown several inches, developed a deep voice, and become awkward and clumsy, as if he could not get used to his new, larger body. Last night, after the incident with the jar of oil, Pa had announced that Philemon was now too big for serious thieving, and henceforth it was Gwenda’s job.

That was why she had lain awake for so much of the night.

Philemon’s name was really Holger. When he was ten years old, he had decided he was going to be a monk, so he told everyone he had changed his name to Philemon, which sounded more religious. Surprisingly, most people had gone along with his wish, though Ma and Pa still called him Holger.

They passed through the door and saw two lines of shivering nuns holding burning torches to light the pathway from the hospital to the great west door of Kingsbridge Cathedral. Shadows flickered at the edges of the torchlight, as if the imps and hobgoblins of the night were cavorting just out of sight, kept at a distance only by the sanctity of the nuns.

Gwenda half expected to see Hop waiting outside, but he was not there. Perhaps he had found somewhere warm to sleep. As they walked to the church, Pa made sure they stayed close to Sir Gerald. From behind, someone tugged painfully at Gwenda’s hair. She squealed, thinking it was a goblin; but when she turned she saw Wulfric, her six-year-old neighbour. He darted out of her reach, laughing. Then his father growled “Behave!” and smacked his head, and the little boy began to cry.

The vast church was a shapeless mass towering above the huddled crowd. Only the lowest parts were distinct, arches and mullions picked out in orange and red by the uncertain torchlight. The procession slowed as it approached the cathedral entrance, and Gwenda could see a group of townspeople coming from the opposite direction. There were hundreds of them, Gwenda thought, maybe thousands, although she was not sure how many people made a thousand, for she could not count that high.

The crowd inched through the vestibule. The restless light of the torches fell on the sculpted figures around the walls, making them dance madly. At the lowest level were demons and monsters. Gwenda stared uneasily at dragons and griffins, a bear with a man’s head, a dog with two bodies and one muzzle. Some of the demons struggled with humans: a devil put a noose around a man’s neck, a fox-like monster dragged a woman by her hair, an eagle with hands speared a naked man. Above these scenes the saints stood in a row under sheltering canopies; over them the apostles sat on thrones; then, in the arch over the main door, St Peter with his key and St Paul with a scroll looked adoringly upwards at Jesus Christ.

Gwenda knew that Jesus was telling her not to sin, or she would be tortured by demons; but humans frightened her more than demons. If she failed to steal Sir Gerald’s purse, she would be whipped by her father. Worse, there would be nothing for the family to eat but soup made with acorns. She and Philemon would be hungry for weeks on end. Ma’s breasts would dry up, and the new baby would die, as the last two had. Pa would disappear for days, and come back with nothing for the pot but a scrawny heron or a couple of squirrels. Being hungry was worse than being whipped – it hurt longer.

She had been taught to pilfer at a young age: an apple from a stall, a new-laid egg from under a neighbour’s hen, a knife dropped carelessly on a tavern table by a drunk. But stealing money was different. If she were caught robbing Sir Gerald it would be no use bursting into tears and hoping to be treated as a naughty child, as she had once after thieving a pair of dainty leather shoes from a soft-hearted nun. Cutting the strings of a knight’s purse was no childish peccadillo, it was a real grown-up crime, and she would be treated accordingly.

She tried not to think about it. She was small and nimble and quick, and she would take the purse stealthily, like a ghost – provided she could keep from trembling.

The wide church was already thronged with people. In the side aisles, hooded monks held torches that cast a restless red glow. The marching pillars of the nave reached up into darkness. Gwenda stayed close to Sir Gerald as the crowd pushed forward towards the altar. The red-bearded knight and his thin wife did not notice her. Their two boys paid no more attention to her than to the stone walls of the cathedral. Gwenda’s family fell back and she lost sight of them.

The nave filled up quickly. Gwenda had never seen so many people in one place: it was busier than the cathedral green on market day. People greeted one another cheerfully, feeling safe from evil spirits in this holy place, and the sound of all their conversations mounted to a roar.

Then the bell tolled, and they fell silent.

Sir Gerald was standing by a family from the town. They all wore cloaks of fine cloth, so they were probably rich wool dealers. Next to the knight stood a girl about ten years old. Gwenda stood behind Sir Gerald and the girl. She tried to make herself inconspicuous but, to her dismay, the girl looked at her and smiled reassuringly, as if to tell her not to be frightened.

Around the edges of the crowd the monks extinguished their torches, one by one, until the great church was in utter darkness.

Gwenda wondered if the rich girl would remember her later. She had not merely glanced at Gwenda then ignored her, as most people did. She had noticed her, had thought about her, had anticipated that she might be scared, and had given her a friendly smile. But there were hundreds of children in the cathedral. She could not have got a very clear impression of Gwenda’s features in the dim light… could she? Gwenda tried to put the worry out of her mind.

Invisible in the darkness, she stepped forward and slipped noiselessly between the two figures, feeling the soft wool of the girl’s cloak on one side and the stiffer fabric of the knight’s old surcoat on the other. Now she was in a position to get at the purse.

She reached into her neckline and took the little knife from its sheath.

The silence was broken by a terrible scream. Gwenda had been expecting it – Ma had explained what was going to happen during the service – but, all the same, she was shocked. It sounded like someone being tortured.

Then there was a harsh drumming sound, as of someone beating on a metal plate. More noises followed: wailing, mad laughter, a hunting horn, a rattle, animal noises, a cracked bell. In the congregation, a child started to cry, and others joined in. Some of the adults laughed nervously. They knew the noises were made by the monks, but all the same it was a hellish cacophony.

This was not the moment to take the purse, Gwenda thought fearfully. Everyone was tense, alert. The knight would be sensitive to any touch.

The devilish noise grew louder, then a new sound intervened: music. At first it was so soft that Gwenda was not sure she had really heard it, then gradually it grew louder. The nuns were singing. Gwenda felt her body flood with tension. The moment was approaching. Moving like a spirit, imperceptible as the air, she turned so that she was facing Sir Gerald.