She led him to the sheds at the harbor’s far end, where he had first met her at one of the biremes under construction. He once more saw the supports holding the vessel in the air over the tiered depression in the ground. It was late afternoon, and the workers had gone for the day, meaning that the two of them were alone.

‘Understand anything about carpentry?’ she asked.

Dion smiled. ‘Not much.’

‘Know what a mortise and tenon joint is?’ When he didn’t respond, she continued. ‘Imagine you’re trying to fit two pieces of wood together at an angle. You need something strong to hold them together; a few wooden dowels aren’t enough to do the trick. Come.’ She walked down the outside of the ship, weaving around the supports, until she came to the ribs on the hull. ‘See here? The wood fits seamlessly together. The best way to understand it is to think of the parts of a man and woman.’ She grinned. ‘We shape the end to give this plank here’—she touched one of the horizontal pieces of what would become the deck—‘a tooth . . . an appendage . . . a man’s knob. Whereas this rib here’—Roxana slapped the wood—‘we gouge so that we have a hole. Understand?’

Dion ran his eyes over the warship, and now that he was looking, he could see where every joint had been carefully fitted to connect one piece of timber to another. ‘How long are the teeth?’

‘At least as long as what you have in your trousers.’ She chuckled. ‘Sometimes a lot longer.’

‘Where do you get the timber?’

‘The pine comes from central Salesia. We also use oak for extra strength.’

‘How is the wood warped?’

‘Heat. We soak the timber then bend it over iron.’

The more Dion learned, the more there was to learn. The carpenters in Xanthos would know most of what Roxana was telling him. But to make one of these ships, a bireme, would require intimate knowledge of stresses and forces, combined with precise measurement and, most of all, experience.

‘The hull is built first, completely finished before we work on the decking and the interior.’ Roxana looked at the vessel proudly. ‘She’s given a shallow draft not just so we can beach her, but also so she’s agile and can turn quickly.’

‘How far away is this one from completion?’ Dion asked. He could see that the hull was close to finished, although much of the exterior planking still needed to be laid over the ribs.

‘Another six months,’ she said. ‘At least.’