The crisis came on Whit Monday.

Early in the afternoon Caris happened to be at the fair, taking a stroll after dinner, looking around. It was quiet by comparison with the old days, when hundreds of visitors and thousands of townspeople thronged not just the cathedral green but all the principal streets. Nevertheless, this year’s fair was better than expected after last year’s cancellation. Caris figured that people had noticed how the grip of the plague seemed to be weakening. Those who had survived so far thought they must be invulnerable – and some were, though others were not, for it continued to kill people.

Madge Webber’s cloth was the talking point of the fair. The new looms designed by Merthin were not just faster – they also made it easier to produce complex patterns in the weave. She had sold half her stock already.

Caris was talking to Madge when the fight started. Madge was embarrassing her by saying, as she had often said before, that without Caris she would still be a penniless weaver. Caris was about to give her customary denial when they heard shouts.

Caris recognized immediately the deep-chested sound of aggressive young men. It came from the neighbourhood of an ale barrel thirty yards away. The shouts increased rapidly, and a young woman screamed. Caris hurried over to the place, hoping to stop the fight before it got out of control.

She was a little too late.

The fracas was well under way. Four of the town’s young tearaways were fighting fiercely with a group of peasants, identifiable as such by their rustic clothing, and probably all from the same village. A pretty girl, no doubt the one who had screamed, was struggling to separate two men who were punching one another mercilessly. One of the town boys had drawn a knife, and the peasants had heavy wooden shovels. As Caris arrived, more people were joining in on both sides.

She turned to Madge, who had followed her. “Send someone to fetch Mungo Constable, quick as you can. He’s probably in the basement of the guild hall.” Madge hurried off.

The fight was getting nastier. Several town boys had knives out. A peasant lad was lying on the ground bleeding copiously from his arm, and another was fighting on despite a gash in his face. As Caris watched, two more townies started kicking the peasant on the ground.

Caris hesitated another moment, then stepped forward. She grabbed the nearest fighter by the shirt. “Willie Bakerson, stop this right now!” she shouted in her most authoritative voice.

It almost worked.

Willie stepped back from his opponent, startled, and looked at Caris guiltily. She opened her mouth to speak again, but at that instant a shovel struck her a violent blow on the head that had surely been intended for Willie.

It hurt like hell. Her vision blurred, she lost her balance, and the next thing she knew she hit the ground. She lay there dazed, trying to recover her wits, while the world seemed to sway around her. Then someone grabbed her under the arms and dragged her away.

“Are you hurt, Mother Caris?” The voice was familiar, though she could not place it.

Her head cleared at last, and she struggled to her feet with the help of her rescuer, whom she now identified as the muscular corn merchant Megg Robbins. “I’m just a bit stunned,” Caris said. “We have to stop these boys killing each other.”

“Here come the constables. Let’s leave it to them.”

Sure enough, Mungo and six or seven deputies appeared, all wielding clubs. They waded into the fight, cracking heads indiscriminately. They were doing as much damage as the original fighters, but their presence confused the battleground. The boys looked bewildered, and some ran off In a remarkably few moments the fight was over.

Caris said: “Megg, run to the nunnery and fetch Sister Oonagh, and tell her to bring bandages.”

Megg hurried away.

The walking wounded quickly disappeared. Caris began to examine those who were left. A peasant boy who had been knifed in the stomach was trying to hold his guts in: there was little hope for him. The one with the gashed arm would live if Caris could stop the bleeding. She took off his belt, wound it around his upper arm and tightened it until the flow of blood slowed to a trickle. “Hold that there,” she told him, and moved on to a town boy who seemed to have broken some bones in his hand. Her head was still hurting but she ignored it.

Oonagh and several more nuns appeared. A moment later, Matthew Barber arrived with his bag. Between them they patched up the wounded. Under Caris’s instructions, volunteers picked up the worst victims and carried them to the nunnery. “Take them to the old hospital, not the new one,” she said.

She stood up from a kneeling position and felt dizzy. She grabbed Oonagh to steady herself. “What’s the matter?” said Oonagh.

“I’ll be all right. We’d better get to the hospital.”

They threaded their way through the market stalls to the old hospital. When they went in they saw immediately that none of the wounded were here. Caris cursed. “The fools have taken them all to the wrong place,” she said. It was going to take a while for people to learn the importance of the difference, she concluded.

She and Oonagh went to the new building. The cloister was entered through a wide archway. As they went in, they met the volunteers corning out. “You brought them to the wrong place!” Caris said crossly.

One said: “But, Mother Caris-”

“Don’t argue, there’s no time,” she said impatiently. “Just carry them to the old hospital.”

Stepping into the cloisters, she saw the boy with the gashed arm being carried into a room where, she knew, there were five plague victims. She rushed across the quadrangle. “Stop!” she yelled furiously. “What do you think you’re doing?”

A man’s voice said: “They are carrying out my instructions.”

Caris stopped and looked around. It was Brother Sime. “Don’t be a fool,” she said. “He’s got a knife wound – do you want him to die of the plague?”

His round face turned pink. “I don’t propose to submit my decision to you for approval, Mother Caris.”

That was stupid and she ignored it. “All these injured boys must be kept away from plague victims, or they’ll catch it!”

“I think you’re overwrought. I suggest you go and lie down.”

“Lie down?” She was outraged. “I’ve just patched up all these men – now I’ve got to look at them properly. But not here!”

“Thank you for your emergency work, mother. You can now leave me to examine the patients thoroughly.”

“You idiot, you’ll kill them!”

“Please leave the hospital until you have calmed down.”

“You can’t throw me out of here, you stupid boy! I built this hospital with the nuns’ money. I’m in charge here.”

“Are you?” he said coolly.

Caris realized that, although she had not anticipated this moment, he almost certainly had. He was flushed but he had his feelings under control. He was a man with a plan. She paused, thinking fast. Looking around, she saw that the nuns and volunteers were all watching, waiting to see how this would turn out.

“We have to attend to these boys,” she said. “While we’re standing here arguing, they’re bleeding to death. We’ll compromise, for now.” She raised her voice. “Put every one down exactly where they are, please.” The weather was warm, there was no need for the patients to be indoors. “We’ll see to their needs first, then decide later where they are to be bedded.”

The volunteers and nuns knew and respected Caris, whereas Sime was new to them; and they obeyed her with alacrity.

Sime saw that he was beaten, and a look of utter fury came over his face. “I cannot treat patients in these circumstances,” he said, and he stalked out.

Caris was shocked. She had tried to save his pride with her compromise, and she had not thought he would walk away from sick people in a fit of petulance.