‘Do you really want the details? Look, there are bladders here which, if filled with water, might cause the craft to sink, and if pumped out could make it float. It would certainly make sense of the fish shape, wouldn’t it? And think of the advantage, Ibrahim. A boat that could float under your enemy’s fleet, all unseen, and attack from below.’

Ibrahim tossed aside the bit of parchment. ‘This is such a waste of time. It always was.’

‘The emir may not think so when we demonstrate our weapons to him.’

‘And when will that be?’

Peter shifted, uncomfortable. ‘We have a number of designs, partially realised . . . We aren’t ready yet.’

‘Allah preserve us, but the Christian armies are close. Surely even a bookworm like you is aware of that.’

‘Of course I am. We’re all working as hard as we can, and as fast.’

‘What of your conscience, Peter? Are you happy as a Christian to be arming Muslims?’

‘I think of myself as a scholar before I’m a Christian. And this is a scholarly project, whatever else it is. I’m curious, Ibrahim. Anyway, perhaps our weapons, if they deter Fernando, will prevent war, rather than provoke it. Have you thought of that? In a way we’re alike, aren’t we, Ibrahim? Both striving to save people from harm, in our different ways.’

Ibrahim thought this was all artifice, and he said nothing. The thoughtful young man he had met five years ago was being eroded away by ambition and a certain flavour of greed - not greed for wealth, but for accomplishment and recognition. He had seen it in scholars before, in his time at the court. Such men would do anything to stand out from their peers.

Peter was watching him. ‘You know, we do miss you, Ibrahim. When I first met you I took you for a bone-headed dolt. A slab of righteous muscle.’

‘I wasn’t twenty years old!’

‘Now you’re five years older, and your true qualities are emerging. You’re no soldier, for all you wear that scimitar at your waist. You’re far more than that. You have a set of skills your mother could put to good use - organisation, leadership. You should make your peace with Subh. She misses you.’

‘My relationship with my mother is not a matter for you, but for my conscience. And I believe I put my skills to good use here. There is an emergency in the city. Again, even you must be aware of that...’