‘For Genoa,’ Swan said piously.

‘Bah. Stupid foreigners.’ The merchant went over the side.

The English ship departed the port of Alexandra before darkness fell. She was a big round ship, as big as the Venetians’ and heavily built – not fast, but a virtual fortress, high off the water and with heavy fighting castles.

Fra Tommaso sat on the edge of his own bunk, dabbing Swan’s forehead and eyes with a damp cloth. Swan had a headache like that of a man who had drunk a great deal of alcohol – another thing he hadn’t done.

‘Your Englishmen seemed to obey you quite readily,’ the old man said softly. ‘Where did you send them?’

‘Phokaia, for alum,’ Swan said. ‘He had a firman from the Sultan in Constantinople. The Genoese was being a fool.’

‘That is why the Genoese are losing their empire,’ Fra Tommaso said. ‘They’ve created a race of rich, entitled fools who can no longer see beyond their own greed. Why are men so vicious? It is no wonder God has sent us Mehmet. It is what we deserve.’

Swan closed his eyes and thought of Khatun Bengül. He’d been in Alexandria three days, and somehow he hadn’t managed even the most casual encounter.

Chastity pained him like alum on an open cut.

The galley sailed north with the dawn, and spent three weeks beating up against the winds – rowing into headwinds that exhausted the rowers and sheltering in coves, first in Cyprus and then on the south coast of Asia. Finally they made Rhodos. The rowers didn’t even get to leave the ship. Half a dozen young French knights came aboard as soon as they beached, and another dozen archers.

‘Chios is under attack,’ Fra Tommaso said. ‘You may get to see it yet.’

They filled their water jars and their biscuit bin and went back to sea, oarsmen cursing. But after a few hours, when a favourable southerly filled the mainsail, the oarsmen had all of their fighting kit filling the benches and the catwalk – mail was polished, and swords and glaives and vicious short javelins were touched up and sharpened, had new oil applied, and the like. The archers took out small whetstones and retouched their best points.

‘How bad is it?’ Swan asked.

Fra Tommaso shrugged and spat downwind.

‘Bad enough, eh? The rumour is the Grand Turk has sent one of his great lords to sea with a fleet – a hundred galleys and fifty troopships. They intend to land and take Lesvos and Chios. A French pilgrim says the rumour in Aleppo is that they’ll go for Rhodos itself.’ The old knight smiled wickedly. ‘To stop the Turks, the order has three good galleys and two very decrepit ones, as well as a dozen smaller ships and about two thousand men. We should be fine.’

Swan went to sharpen his sword.

When it was his turn at the tiller, he noticed how the load of armoured men changed the ship’s handling – the fineness of her entry was altered, and the way she turned. And the rate of her acceleration and deceleration under oars. The ship was heavier by almost twenty men and their gear, and the men were all topside, on the weather decks, where their weight had the most effect on the narrow ship’s balance.

However, no one watched him while he steered. He liked that part.

He also liked the new device a pair of Burgundian mercenaries brought aboard – a fire discharger made of iron and built like a barrel, with long staves and hoops. It was mounted on the galley’s bulwarks at the gunwale, and the two Burgundians said it would throw a one-ounce ball five hundred paces and pierce armour.

Swan pretended to believe them, admired its ugly deadliness, and went back to his hammock.

They camped on a beach on the south end of Chios. Swan had never smelled mastic before – the scent was heady. He climbed the beach, under the watchful eye of a shepherd. Two men with crossbows eyed him carefully from a tower which proved to guard a small grove of the trees that gave the world’s richest resin.

One of the guards threw something at him. He laughed, and pointed.

It is possible to look at a man’s face and conclude that he’s not offering violence. Swan was sure – despite the throw – that the man meant it in a good-natured way. After a moment of confusion, he looked around until he found the rock the man had thrown.

But it wasn’t rock. It was a solid mass of resin the size of his hand. He picked it up and waved it at the guards, who waved back. Then, after clearing a section of sand on his lump, he flaked off a small piece and put it in his mouth.

It was a little like chewing pine tar. But all his life he’d heard it described as good for teeth, so he continued chewing for some time, while he looked at the walls, the orchards and the rock.

He walked back to the base of the tower and shouted up. ‘Greetings! Can you understand me?’ in Greek.

They understood well enough. The smaller man came down the wooden tower immediately and opened a door. ‘A Frank who speaks Greek? This is a great wonder,’ the man said.

Swan laughed. ‘Thanks for the mastic.’

‘Think nothing of it!’ the man said. ‘It’s dull here. But so many men come to steal it – it defies belief, the viciousness of the barbarians. Genoese and Turks – much the same, eh? Oh – my pardon if you are in fact Genoese.’

‘I am in fact a Frank from England. Thule. Far to the north.’ Swan looked at the tower. ‘This is all to guard the mastic?’

‘North of Lesvos? That’s not Thule. There’s Samothrace, I suppose.’ The man shrugged. ‘And then the mainland and Thrace. Thessalonika, I hear, is quite a city. You are from north of Thessalonika?’

Swan suspected that geography was not going to be the key to the conversation. ‘I’m looking to find some people …’ he said.

‘Franks always are. Listen – you seem nice enough. Here on Chios, when Franks come to collect rents – often they are killed and their bodies left to the beasts. Eh? And yes, my foreign friend, this is all to guard mastic. See all the rock? It is very hard to grow barley here. Barley is at the north end of the island. Even sheep hate this rock. Eh?’ He grinned. ‘If God had not given us mastic, we’d have nothing.’

Swan nodded sagely. ‘I will consider what you say, as I have very little interest in being killed as a tax collector.’

‘In this you show real wisdom,’ said the man.

‘You know there is a Turk fleet on its way here?’ Swan asked.

‘Pagans as well as thieves. This is why God has given us the crossbow.’ The Greek islander was missing no teeth – indeed, his head seemed to be full of them. He was an excellent advertisement for mastic.

‘Have you seen them?’ Swan asked.

‘Of course!’ the Greek answered.

Swan dug in his purse and produced a nameless silver coin roughly the size of a silver mark from England. And worn perfectly flat.

The man made it disappear with the same facility as that with which Swan had made it appear. ‘Two days ago. Two galleys. They watered south of Mesta. You are very polite, for a Frank.’

Swan shared some wine from his leather bottle and the man found him even more polite and offered him several pounds of mastic.

‘At a very good price,’ he added.

After some genteel dickering, Swan carried away about twenty pounds of the stuff. He had no idea if he’d been swindled or not. It seemed cheap enough. Five gold ducats had purchased the whole basket. He carried it down to the ship, almost lost his investment trying to negotiate the beach, and then spent his evening rebagging the whole and putting it in waxed linen. He pointed the bags out to Peter. ‘That’s your wages,’ he said.

Peter frowned. ‘I am not so well paid, I tink.’

Swan found the galley’s commander working on his own armour, and passed the news of the Turkish galleys. Fra Tommaso nodded. ‘Could be true. You have to be leery of these heretics. Many of them prefer the Turks to us. Eh? Be a good lad and do my tassets, please?’