In Greek, Swan roared, ‘All of you are free! The bishop says so! Go – quickly! Out the gates! Go!’

The slaves stopped pressing in.

There was a moment . . .

Then there was a roar, or rather, a deep murmur, as the slaves began to comprehend what had been said. At the back of the crowd, slaves were running for the gate.

Archers began to loose shafts at them from the towers. And then the screams began.

‘Forward!’ roared Alessandro. ‘Cut your way through if you must.’

Swan still had his helmet under his arm. Now it seemed like a foolish liability. He wasn’t going to put it on his head.

He drew his sword.

The bishop had stopped. He was trying to shepherd five slaves. He touched them, grabbed their hands . . .

One of them took a Turkish arrow in the gut. The man sat abruptly, legs spread, the arrow sticking out of his back. He fell forward a little, and blood ran out of his mouth, but he didn’t scream. He just looked . . . surprised.

The bishop began to weep.

He was holding the hand of a little girl, and trying to drag her along, and a woman – her mother? – followed them, reaching for the girl.

An arrow struck her, and she fell.

Swan swept the little girl up and held her in his helmet arm, and ran for the gate.

No arrows touched him.

The bishop grabbed another child and dragged him along behind. The child screamed. The child’s father called ‘Run, run!’ in Greek.

Looking back from the gate, Swan could see very few bodies, and a great deal of screaming panic.

They ran through the gate, and out into the main thoroughfare of the northern part of the city – almost like a country road, so far from the inhabited core.

But there was no Turkish ambush. A dozen mounted Turks were quietly rounding up the slaves, but they offered no violence to the embassy. They did smile, and laugh, and point.

Alessandro didn’t stop moving. ‘This way,’ he called, and they were off, across a rubble-strewn field where once there had been a set of noblemen’s houses. The child sitting on Swan’s arm seemed to weigh ten stone, and he cursed the useless helmet. He was breathing like a bellows.

The mounted Turks watched them go, laughing and calling things.

They went almost a quarter-mile across the rubble, down old streets with no buildings left on either side, and through a great field that looked as if it had been recently burned.

A great semicircle of churches, their gold or bronze domes rising above buildings, tenements and rubble, marked the edge of the inhabited city, still another quarter of a mile away. To the north, behind them, a column of mounted Turks trotted out of the Blacharnae Palace.

‘We’ve come away with nine slaves,’ Alessandro said. He motioned for them to stop, and everyone – armoured or not – stood, virtually unable to speak, breathing like so many armourer’s bellows.

‘If I escape this, I will burn a hundred candles of white wax on the altar of Saint Mark,’ panted one of the young Venetian men-at-arms.

Cesare simply leaned over and threw up. He did it neatly, wih the economy of the heavy drinker, and then he spat.

Swan had a water bottle, and he passed it to his friend, who raised it in a mock toast. ‘When I die, see that Donna Lucrescia has all my love, and give my money to the poor.’ He stood bent over, and his breaths came in great gasps.

Alessandro was watching the Turks to the north. Ahead of them, at the edge of the suburbs, there was a low roar like distant surf.

Alessandro rubbed his chin. ‘I’m going to assume, for the sake of speed, that you ignored my advice and took some petty revenge on Omar Reis.’

Swan looked at the Turks. ‘I—’

Alessandro raised a hand, forestalling argument. ‘I have misspent my life, wasted my patronage, squandered my father’s money, and lived a life steeped in sin. Despite which, I’m not sure I ever managed to be so complete a dangerous, ignorant fool as you.’ He shrugged. ‘Although I admit that you perform these little miracles of idiocy with a certain sprezzatura.’

‘What did you do?’ gasped Cesare. ‘Sleep with his wife?’

‘Daughter,’ said Swan, with some pride mixed with regret.

Cesare laughed. ‘I’m so glad I’m about to die in a great crusade – a true reflection of the state of the faith, by God! We are not a handful of Christians standing against the horses of Islam! We’re a dozen dupes of Thomas Swan’s love affair!’ He laughed.

‘He wasn’t going to let us go,’ Swan argued. There was a whine in his voice.

‘He might have,’ Alessandro said. ‘He might not have. I’m sure you made the Sultan’s choice easier.’ He spat. Pointed with the dagger in his right fist. ‘See the crowd?’ he said.

Cesare shook his head. ‘They look like Greeks.’

‘They are Greeks,’ Alessandro said. ‘The Turks have raised the city against us.’

‘But they’re Christians!’ said one of the Venetians.

Swan looked at the bishop. ‘We represent the Pope,’ he said bitterly. ‘Most of the Greeks hate the Pope worse than the Sultan.’ He glared at Alessandro. ‘You can’t pin that one on me. That crowd was fanned to flames before . . .’

Alessandro smiled his hard, killing smile. ‘I agree. There is plenty of blame to go around.’ He bit his lip. ‘How far to the first cistern?’

Swan shrugged. ‘A mile, at least. There’s an aqueduct above the Plataea, so there must be an entrance there.’

Giannis was talking quickly to one of the freed slaves, a woman of forty. He was begging her to precede them and proclaim to the crowd that the bishop had saved her. He promised her a place aboard their ship.

She stared at him, blank eyed.

When they rose to their feet, she just sat, head down.

So they went towards the crowd with only eight slave children as their protection.

The crowd was led by priests – at least a dozen of them. Giannis went forward to negotiate, and was hit with a paving stone. Luckily, the stone hit the peak of his helmet, but the message was clear, and his shouts in Greek were ignored.

‘The Turks have set this up beautifully,’ Alessandro said. ‘We will be murdered by a Greek crowd. Or we kill our way through a Greek crowd. Either way, the Sultan wins.’

The bishop emerged from his escort. He wasn’t a tall man, just middle height, with mouse-brown hair and a weak chin. But he took his bishop’s crozier back from a terrified sailor. His hands shook. But he set his face.

‘I forbid you to kill them,’ he said.

‘Excellency,’ said Alessandro. He bowed his head.

The bishop threw his outer robe around his shoulders and put his mitre on his head, and began to walk towards the crowd.

A young man threw a paving stone too big for him. It didn’t come close to the bishop, but it started a horde of small boys throwing clods of earth. The bishop kept walking across the rubble.

In some ways, it was the bravest thing Swan had ever seen. Nothing in the bishop’s previous behaviour had led him to expect this – but in his heart, he was impressed.

He thought of profit, and loss, and all the effort he’d put into his plan, and he shook his head once, and said, ‘Fuck,’ very clearly, in English.

Then he put the small girl down, and took his helmet, a fine Milanese armet, out from under his arm. His arm was cramping. He opened the visor, dropped the falling buff, and peeled back the hinged cheek plates.

Inside lay the fantastical jewelled reliquary of the head of St George. He held it high above his head, and followed the bishop.

The head, and the children, got them through the crowd alive, unharmed and unblooded.

One of the priests offered to guide them, and the party began to work their way south and east through the suburbs – mostly abandoned, with groups of occupied houses like tiny villages set among the crumbling ruins of others abandoned a few months, a few years or a few centuries before.