The physical effort of running through the streets calmed her a little, and she was in control of her emotions by the time she came to Mattie’s house. Mattie would know what to do. She would say: I’ve seen this before, I know what will happen next, here’s the treatment that helps.

Caris banged on the door. Hearing no immediate answer, she impatiently tried the latch and found it open. She dashed inside, saying: “Mattie, you have to come to the hospital right away, it’s my father!”

The front room was empty. Caris pulled aside the curtain that screened off the kitchen. Mattie was not there, either. Caris said aloud: “Oh, why would you be out of the house at this very moment?” She looked around for some clue as to where Mattie might have gone. Then she noticed how stripped the room appeared. All the little jars and bottles had gone, leaving the shelves bare. There were none of the mortars and pestles Mattie used for grinding ingredients, none of her small pots for melting and boiling, no knives for chopping herbs. Caris returned to the front half of the house and saw that Mattie’s personal possessions had also disappeared: her sewing box, her polished wood cups for wine, the embroidered shawl she had hung on the wall for decoration, the carved bone comb she treasured.

Mattie had packed up and gone.

And Caris could guess why. Mattie must have heard about Philemon’s questions in church yesterday. Traditionally, the ecclesiastical court held a session on the Saturday of Fleece Fair week. Only two years ago the monks had used the occasion for the trial of Crazy Nell on the absurd charge of heresy.

Mattie was no heretic, of course, but it was difficult to prove that, as many old women had learned. She had calculated her chances of surviving a trial, and found the answer frightening. Without telling anyone, she had packed up her possessions and left town. Probably she had found a peasant returning home after selling his produce, and persuaded him to take her on his ox-cart. Caris imagined her leaving at first light, her box beside her on the cart, the hood of her cloak pulled forward to hide her face. No one could even guess where she had gone.

“What am I going to do?” Caris said to the empty room. Mattie knew better than anyone else in Kingsbridge how to help sick people. This was the worst possible moment for her to disappear, just when Edmund lay unconscious in the hospital. Caris felt despair.

She sat down on Mattie’s chair, still panting from the effort of running. She wanted to run back to the hospital, but there was no point. She would not be able to help her father. Nobody could.

The town must have a healer, she thought; one who does not rely on prayers and holy water, or bleeding, but uses simple treatments that have been shown to work. And as she sat in Mattie’s empty house, she realized that there was one person who could fill the role, someone who knew Mattie’s methods and believed in her practical philosophy. That person was Caris herself.

The thought burst on her with the blinding light of a revelation, and she sat dead still, bewildered by the implications. She knew the recipes for Mattie’s main potions: one for easing pain, one to cause vomiting, one for washing wounds, one to bring down a fever. She knew the uses of all the common herbs: dill for indigestion, fennel for fever, rue for flatulence, watercress for infertility. She knew the treatments Mattie never prescribed: poultices made with dung, medicines containing gold and silver, verses written on vellum and bound to the ailing part of the body.

And she had an instinct for it. Mother Cecilia had said so, had practically pleaded with Caris to become a nun. Well, she was not going to enter the priory, but she might perhaps take Mattie’s place. Why not? The cloth business could be run by Mark Webber – he was doing most of the work anyway.

She would seek out other wise women – in Shiring, in Winchester, perhaps in London – and question them about their methods, what succeeded and what failed. Men were secretive about their craft skills – their ‘mysteries’ as they called them, as if there were something supernatural about tanning leather or making horseshoes – but women were usually willing to share knowledge with other women.

She would even read some of the monks’ ancient texts. There might be some truth in them. Perhaps the instinct that Cecilia attributed to her would help her winnow the seeds of practical treatment from the chaff of priestly mumbo-jumbo.

She stood up and left the house. She walked slowly back, dreading what she would find at the hospital. She felt fatalistic now. Her father would either be all right, or he would not. All she could do was carry out her resolution so that in future, when the people she loved were sick, she would know she was doing everything possible to help them.

She fought back tears as she made her way through the fair to the priory buildings. When she entered the hospital, she hardly dared look at her father. She approached the bed, which was surrounded by people: Mother Cecilia, Old Julie, Brother Joseph, Mark Webber, Petranilla, Alice, Elfric.

What must be, must be, she thought. She touched the shoulder of her sister, Alice, who moved aside, making room. At last Caris looked at her father.

He was alive and conscious, though he looked pale and tired. His eyes were open, and he looked straight at her and tried a weak smile. “I’m afraid I gave you a scare,” he said. “I’m sorry, my dear.”

“Oh, thank God,” said Caris, and she began to cry.

On Wednesday morning Merthin came to Caris’s stall in consternation. “Betty Baxter just asked me a strange question,” he said. “She wanted to know who was going to stand against Elfric in the election for alderman.”

“What election?” Caris said. “My father is alderman… oh.” She realized what must be going on. Elfric was telling people that Edmund was too old and sick to fulfil the role, and the town needed someone new. And he was presenting himself as a candidate. “We must tell my father right away.”

Caris and Merthin left the fairground and crossed the main street to the house. Edmund had left the priory hospital yesterday, saying – correctly – that there was nothing the monks could do for him but bleed him, which made him feel worse. He had been carried home, and a bed had been made up for him in the parlour on the ground floor.

This morning he was reclining on a stack of pillows in his improvised bed. He looked so weak that Caris hesitated to bother him with the news, but Merthin sat down beside him and laid out the facts starkly.

“Elfric is right,” Edmund said when Merthin had finished. “Look at me. I can hardly sit upright. The parish guild needs strong leadership. It’s no job for a sick man.”

“But you’ll be better soon!” Caris exclaimed.

“Perhaps. But I’m getting old. You must have noticed how absent-minded I’ve become. I forget things. And I was fatally slow to react to the downturn in the market for raw wool – I lost a lot of money last year. Thank God, we’ve rebuilt our fortune with the scarlet cloth – but you did that, Caris, not me.”

She knew all that, of course, but still she felt indignant. “Are you just going to let Elfric take over?”

“Certainly not. He would be a disaster. He’s too much in thrall to Godwyn. Even after we become a borough, we’ll need an alderman who can stand up to the priory.”

“Who else could do the job?”

“Talk to Dick Brewer. He’s one of the richest men in town, and the alderman must be rich, to have the respect of the other merchants. Dick’s not afraid of Godwyn or any of the monks. He’d be a good leader.”

Caris found herself reluctant to do as he said. It seemed like accepting that he was going to die. She could not remember a time when her father had not been alderman. She did not want her world to change.