Brother Peter looked curiously at her as they went together down the cobbled steps. ‘Don’t you want to confess your soul and attend the service now that you have seen God work in such a mysterious way? Should you not turn to our God, now that you have been in such danger? I could explain our beliefs to you. I could convert you.’

Ishraq smiled at him, indifferent to his concern. ‘Ah, Brother Peter, I know you are a good man and would like to save my soul. I don’t know what caused the wave. But it doesn’t inspire me to pray to your God.’

Isolde agreed that they should leave the following day but she could not bring herself to tell Luca. ‘Will you tell him?’ she asked Brother Peter. ‘I can’t bear to do it.’

He waited until the hour before dinner while they were all four sitting in the dining room before a smoky fire of damp wood, and then he said quietly, ‘Brother Luca, I think we can do nothing more in this town and I will send my report tomorrow. I will write that we can find no certain explanation for the wave, though some wild thoughts from pagan and heretical writers have been mentioned.’

Luca barely raised his head.

‘And I have found a master who will take us on his ship tomorrow. We can go after Prime.’

‘We stay,’ Luca said instantly. ‘At least for a few more days.’

‘We have a mission; and there is nothing more to be done here,’ Brother Peter repeated steadily. ‘We will send your report tomorrow, we can warn Milord and His Holiness that we have seen a powerful sign of the end of days. We can warn them that a previous earthquake was followed by a wave that was followed by the pestilence called the Black Death. But we serve no one by waiting here – and anyway, if a plague is coming we should leave.’

Isolde reached out and put her cool hand over Luca’s clenched fist as it lay on the table. ‘Luca,’ she said quietly.

He turned to her as if she might have answers to his agonising questions. ‘I can’t go,’ he said passionately. ‘I can’t just sail away from here as if nothing is wrong. I can’t just continue on. Freize came with me, he was following me on this quest. He would never have been here but for love of me. I don’t see how to do it without him. If I had been washed out to sea, he would not have left me. He would not have run for his safety and left me behind.’

‘He would want you to complete your mission,’ Isolde said, trying to comfort him. ‘He was so proud of you. He was so proud that you had been called to this work and that he could serve you.’

At the thought of Freize’s joyful boasting, Luca nearly smiled, but then he shook his head. ‘You must see, I have to stay here until . . .’