Shaking off their sleep, they rose quickly, covering themselves with robes against the cool of the morning. Even in the quiet surroundings of that remote wing of the palace, the sound of anxious voices carried to them, of barked orders and men hurrying to their duties.

There was a knock at the door. A moment later Gerutha entered. Her eyes flicked suspiciously at Erlan, a little circumspect at first. Perhaps she felt shy, or else blamed him for all her mistress’s hardships – and by extension her own. Erlan offered some awkward word of greeting but she cut him off. ‘Yes, yes. I’m glad you’re safe, of course, but there’s something you must see. Both of you.’ She took Lilla’s hand and led her through the drapes onto the balcony. Erlan followed them out, feeling the sudden blaze of the dawn sun strike his face.

‘There!’ exclaimed Gerutha.

But his gaze was already away over the rooftops below them, over the cedar trees bending in the wind and the massive sea walls, out onto the waters of the Bosporus. Because there, filling the strait from one shore to the other, were hundreds of ships.

‘The Arab fleet,’ said Gerutha, and the bells rang out the doom of the city.

They watched for hours as more and more vessels moved north up the straits under black and red sails bulging with the warm wind blowing up from the Sea of Marmara. With every passing ship Erlan felt the hard knot of foreboding grow tighter in his stomach. He listened while Lilla and Gerutha told him what they knew of the siege and the wider war between Byzantine and Arab, feeling like a man come late to a feast.

‘We’ve walked into a hurricane,’ he muttered.

They were astonished how ignorant he was of it all, considering the length of time he had been in the city. He had no idea the city was sealed on the landward side to the west. And no inkling, until now, that it had been standing on the edge of a precipice, waiting for the Arab fleet to arrive and stopper them all up in the city like wasps in a bottle.

The vanguard of the fleet, made up of many hundred-oared war-galleys, had long since vanished out of sight to the north, presumably to drop anchor at some point on the western shore already known to them. After them came hundreds of smaller vessels. Troop-carrying ships, light attack craft, heavyladen supply ships churning through the waves. A world of war processing with stately conceit before the walls of the beleaguered city.

‘Why don’t the Byzantines do something?’ Erlan couldn’t understand it. Hardly a spear’s throw below them, standing on the towers spaced along the sea walls, was an array of machines built for the city’s defence. Yet they all remained still. And the hundreds of Byzantine soldiers manning the parapets merely looked on at their enemy.