Karl shook his head. ‘We should wait for orders,’ he said.

Swan was aiming again.

He heard, very clearly, the unmistakable sound of steel on stone. Or rather, he felt it, rather than heard it. He looked around.

He rammed the goose quill full of black powder into the touch-hole of the gonne. He felt the very slight grinding under his thumb that meant the goose quill was in contact with the powder in the barrel – the main charge.

The Turks had four mantlets set up, and a shower of arrows began to fall on the English wall. The Burgundians backed away down the nearest ladder.

‘Fire?’ Swan said, suddenly feeling foolish. The youngest of the Burgundians, also Karl, had the portfire. And he was climbing down the ladder.

Swan leaned over the wall. ‘Stop. I order you. And get your arses back on the wall or I’ll …’ Swan stopped, unsure what he’d do.

‘We’ll come back when you’ve fired the gonne,’ Elder Karl spat. ‘You’ve overcharged it. It might explode.’

‘Fuck you,’ Swan swore. He pulled the tinder box from his belt purse and struck a spark on to some tinder. He checked his aim one more time and touched the glowing char-cloth to the top of the quill.

The little gonne barked like a bolt of sulphurous lightning. The mouth of the barrel rose a foot in the air and slammed down, and the whole frame jumped back a handspan, smacking into Swan’s arm, which might have been broken if he hadn’t been in plate armour.

Across the ravine, on the hillside opposite, a man was screaming. Otherwise, there was no change – the gonne hadn’t hit anything. And yet a half-dozen Turks suddenly burst from the cover of the mantlets and ran back up their ridge.

Peter loosed three arrows in rapid succession and scored two kills. As the last Turk vanished over the crest, he made a wry face. ‘Niet zo slecht,’ he said. ‘Not bad.’

Sir John appeared from the other side of the English tower. ‘Who fired?’ he demanded.

Swan pointed.

One of the Turks was still screaming, his horrible cries echoing around the ravine in an unnatural way. ‘We killed three,’ he said.

Sir John looked at Old Karl, who was just poking his head over the parapet. ‘We were not to fire without orders,’ he said.

Old Karl looked smug.

Swan was suddenly tired. ‘Why?’ he asked.

‘Because we were ordered not to fire,’ Sir John said gently. ‘Young man, obedience is one of our order’s virtues.’ He nodded to the Burgundians. ‘No more firing without orders.’

‘Ve told him not to fire,’ Karl said. Just at that moment, Swan hated all of them.

Sir John was in full plate, and he didn’t shrug. He stood straighter. ‘It would take the wisdom of Solomon to decide whether it is better to disobey and kill three Turks, or to obey the original order and fail to kill the Turks.’ Sir John’s smile wasn’t genial. He leaned over to Karl, who shrank back. ‘It is Master Swan’s business whether he obeys me. It is your business to obey him. Understand?’

The thin English knight went back towards the tower, his steel sabatons rasping on the stone.

‘Obedience is one of our order’s virtues,’ Peter quoted. ‘Along with chastity and poverty. Master Swan, you have brought us to hell.’

Swan, angry as he was, had other thoughts crowding in. He raised a hand for silence.

There it was again – the sound of steel on stone. Like Sir John’s sabatons. Somewhere under his feet.

‘Peter, did you see what they were doing on the hillside?’ Swan asked.

‘Heh!’ Peter said. ‘Dying?’ He laughed his nasty laugh. ‘Is that the sound their black souls make shrieking to hell?’

‘Before you potted them, Peter.’ Swan was looking out under the shade of his hand again. An arrow was lofted from the beach. Swan ducked back and then popped out from behind another merlon. ‘Hello – look, Peter, I got one!’ he said. From his new angle he could see that there was a Turk lying face down behind the nearest mantlet.

It wasn’t the mantlet at which Swan had fired, but that wasn’t important.

‘Doesn’t it look as if there’s an opening?’ Swan asked.

Peter was sulking. ‘Gekke machine,’ he said. ‘Smells like hell come to earth.’ But after both of them had ducked under a new salvo of arrows, he leaned out and glanced. ‘Too dark,’ he said.

Holes in the ground didn’t interest Peter. But Turkish arrows did, and he began to collect a few. He held them up in the last light. ‘Cane. Beautiful. Why don’t our fletchers make them like this?’ he asked. He picked up his own Turkish bow and fitted one. And watched the rocks by the beach. ‘Show yourself,’ he ordered his master.

Swan leaned out and Peter smiled and loosed.

A second later, a man stood, raised his bow, and Peter’s arrow took him in the chest.

Peter was insufferable for the next hour.

After they were relieved, Swan didn’t unarm. Instead, he picked up a pair of lanterns and a long Arabic headscarf. He stopped by the well in the English tower to drink water.

Peter still had his brigandine on. ‘Vere do you tink you are going?’ he said.

Swan frowned. ‘I want to investigate a theory,’ he admitted.

Peter sighed theatrically.

Fifteen minutes later, they were easing past the stinking privies in near-total darkness. Each of them had lanterns, and both were armed.

‘You are insane. You know that,’ Peter said. ‘Christ Jesus, this smell will never come off my good jack. You deserve to be hanged. Sweet Christ!’

Past the privies, moving very carefully. Past the cat piss. Swan’s boots were silent, but his arm harnesses made distinct sounds each time they tapped against stone.

Into the ancient underground street. ‘Which way do you think we’re going?’ Swan asked Peter.

‘I haf no idea, you madman!’ Peter complained. ‘Ve are in hell.’

Indeed, the hidden under-city of Rhodos was a fair simulacrum of hell. It stank – and it was very hot. And absolutely dark. The lanterns with their olive-oil lamps burned with too little light to illuminate any more than a step or two in front of them.

Swan crept down the ancient street. He could feel the slightest breeze on his face, as he had the last time he’d been here – with Salim.

Far away in the darkness, there was a distinct clank.

He eased the sword in his scabbard. And pressed forward.

After ten slow steps, he reached a cross-tunnel. He ran a gauntleted hand over the stone – held his oil lamp in the tunnel and saw the flame move.

‘This way,’ he said.

He struck his head – a ringing blow that staggered him and might have knocked him unconscious if he hadn’t had a helmet on. When he recovered, he raised his lamp and saw that his cross-street – it had cobbled paving under his booted feet – was only four feet high.

‘Must we do this?’ Peter asked. His voice was very loud.

‘I think the escaped slaves are trying to let the Turks into the town,’ Swan said.

‘Vere the fuck are we?’ Peter asked.

Swan rested a moment, his hips against what he suspected were the under-shorings of the English wall. ‘This is the ancient city,’ he said. ‘Many of the old floors – and old walls – still bear weight. So there are empty spaces – and a path among them. Salim knew it. I didn’t think about it at the time – about who exactly lived down here – but it must be escaped slaves.’

‘And they would help the Turks. Of course they would,’ Peter admitted. ‘So – there is a way out?’

‘Can’t you feel the breeze? They must have opened one – or found an old one. There was a great siege here in antiquity.’ Swan levered himself to his feet, avoided striking his head, and crouched, feeling a variety of pains in his back.

Behind him, Peter asked, ‘Just what do you expect to find? Turks?’

Swan hadn’t really given it any thought. Now that he did think about it …

‘Why not just tell Sir John?’ Peter asked.

‘He thinks me a fool,’ Swan spat.