Petronas’s men had split the Arab intruder force in two like a piece of firewood, bottling up the dozens of spearmen still pouring out of the doors of the Virgin’s basilica into the square. There was one hell of a fight raging back there. But many of the intruders had already broken through and had pushed on for their objective: the inside of the Karisios Gate. With hardly a few dozen Byzantines, Erlan and Einar had set off in headlong pursuit up the hill. But the Arabs had a long start on them and reached the gate first.

Slowed by his ankle, Erlan was one of the last to the inner gates. By the time he joined the fray, the dead lay all around, the air was already rank with blood. Curses rose in clouds above the skirmish line and now arrows began hailing from the walls above as the defenders at last registered the danger. Ahead of him was a riot of slaughter. He was still fifty yards from the gates when the Arabs let out a bellow of triumph. The air groaned with splintering wood. Iron hinges shrieked and a shard of light broke through the gateway.

The gates were opening, and buoyed by the tantalizing glimmer of success, the Arabs whipped themselves to still greater fury, slamming the huge doors against the stone walls and pouring into the killing ground beyond.

‘That ain’t good!’ yelled a voice in Norse. Erlan turned and saw Einar close by him, his face daubed with gore thick as paint. ‘If they take the outer gate, the city will fall.’

Erlan nodded, seeing in his mind a flash of the horrors that would befall the citizens of Byzantium if these troops broke through. Lilla. . . ‘On me, Fat-Belly,’ he snarled, then plunged onward into the canyon of hell.

The raiders raced on, blind to all danger, thirsty to breach the last barrier that held back the fury of ten thousand killers from the city. The fate of the world rested on their shoulders. But the two Northmen flew among them, slaying left and right. Above them the walls of the gatehouse towered, sheer and pitiless, boxing them in while boiling water, flaming arrows, rocks, bricks and burning pitch rained on them in a cataract of death. The screams were deafening, from men dying or fearing death. One man swung his arms blindly, his torso engulfed in a furnace of flames. Another was bludgeoned to the ground as a rock the size of a fist crumpled his helmet. There was a crash a few yards in front, a great hiss of steam, Erlan’s face smarted with flecks of scalding water and a boiling mist billowed past like a ghost. An Arab dropped his spear and clutched at his face, turning blindly. Erlan sank the length of Wrathling into his guts, then tore the blade free in a burst of blood and foul liquid.