‘Exalted,’ Tarfel said, his voice low and hard in the commotion. ‘They are not yet firing to destroy. They are finding their range.’ Shouts went up, signal flags and a horn. The black arrow had hit the bridge. ‘And now they have it.’

Matil went very still. ‘Clear the bridge.’

The shouts continued, orders and reports fighting each other, drowning each other in noise. A very large plume of dark smoke was rising from the engine on the plateau.

It took a moment for the hissing sound to reach them, over the wind and the upheaval on the rampart, a sound like water drops on hot stone, or a thousand angry snakes. The smoke rising from the engine went corpse-grey, billowing outwards and upwards on the wind, then streak after streak flew into the sky. Volley after volley of black arrows rocketed up, some screeching and swerving, most flying true, dozens upon dozens of the projectiles. They flew in a cloud, a screaming flock, blasting black smoke as they arced wide of the city, just as the others, over the walls and dropping against the wind.

When they hit, the sound was rolling thunder. Out of sight around the city’s curve, those on the rampart could only fall silent as the first cracks and pops on the wind were joined by a constant rumble, crashing waves of explosive impacts. Finally, they faded, the last of the black arrows whiffling drunken into the gorge, the smash of their percussion spent. The city stood in silence, choked by the floating drifts of black smoke and stone dust, shocked mute.

Then came the creaking, grinding sound, of shifting, shattered stone. Chel needed no view of the bridge to tell what made it. With initial glacial slowness, the first lumps of ancient stone flaked and fell, followed ever faster by their neighbours, until the tumble and thump of chunks of broken stone echoed around the gorge. Chel pressed his hands to his ears, unable to bear the noise, unwilling to hear the shrieks of anyone caught on the bridge as it fell. Numbness consumed him, an odd distance from the world, the constant sounds of terror and destruction pushed into the background beneath his heartbeat.

His heart was beating very fast.

Shouts reached them, cries and bells from across the city. Messengers pelted from darkened hallways, superfluous.

‘The bridge is fallen,’ Matil said, her eyes glazed.

‘Exalted. Exalted!’ Tarfel was focused on the scene below. ‘The engine is moving.’

The hidden team dragged the great wagon forward, lumbering over the broken ground of the plateau, across the front of the city. Around it. Robed figures scuttled in its wake, its escort sliding around with it.

‘They’re going for the other bridge!’

‘Where are your own engines?’ Chel demanded, his voice scratchy and shrill. ‘Your skein bows, your mangonels?’

‘The Stop,’ she said, gaze still somewhere over the plateau. ‘The city has not faced a hostile army in decades.’

‘Well, it does now.’