‘Yet I am a Jew. My lord, Jews in Navarre are given more latitude than elsewhere in Spain. Your man will die unless I attend him but they do not permit a Jewish doctor to treat a Christian.’ The man’s gentle voice bore no malice.

‘You attend Jean de Grailly,’ said Blackstone. ‘He’s Christian.’

‘Even so, I am obliged to ask permission. As we talk your man is dying.’

‘Then stop talking,’ said Blackstone. ‘You have it. There’s a broken piece of knife blade in his side.’

Ben Josef dipped his head and turned to Godfrey de Claville. ‘I will need two bowls of hot water and clean linen to bind the man’s wound.’

De Claville hesitated for only a second as he glanced at Blackstone and then ordered the men at the door.

‘Sir knight,’ said ben Josef, ‘you will help me.’

‘To do what?’

‘Lift his shoulders. I must remove his tunic and shirt.’

It was obvious no one else had the strength to lift Meulon’s weight. He stepped forward but ben Josef raised a hand.

‘No. Not on the same side as his wound. Your clothes are rank with sweat and dirt. We must take all precautions: the wound is already poisoned. Do it here on the opposite side.’

The surgeon gave his commands with no sign of deference. He was in control. Blackstone did as instructed and the smaller man tugged free Meulon’s garments. The huge man, groggy from pain, groaned and tried to rise. Blackstone’s strength held him still.

‘Meulon, it’s me. I’ve found help for you.’

Meulon gritted his teeth and allowed Blackstone to ease him down again.

Two men came into the room carrying the water and linen the Jew had requested.

‘Put them here,’ said ben Josef, undoing the straps on his satchel and exposing a case full of dark glass bottles. He selected four and laid them side by side, pouring measured amounts from each one into a small glass. Loosening the ties on the oilskin, he unfurled the rolled cloth. Slender instruments of polished steel nestled next to each other. They were burnished from persistent cleaning. Halif ben Josef appeared to mutter a prayer before unclipping the brooch that held his cloak. He pulled off his robe and rolled his sleeves above his elbows. He soaked his hands, twisting and turning them, releasing their grime. When he was satisfied they were clean, he wiped them on a piece of linen and then cast it aside so it would not be used again.

‘What is that?’ said Blackstone, pointing to the small glass of liquid.

‘It is a combination of poisons that can kill but tempered with plants that will balance them and render your man unconscious. A man of his strength and size will need a strong potion. I will inflict great pain on him.’

‘My men use herbs for their wounds. I’ve used henbane before,’ said Blackstone.