'Where have you been?' he said. The cold had reached his throat to chill his words.

For answer his brother hung his head and Carnelian knew. Wrath made him dress with icy speed. He left the cell to go hunting for the Lord Jaspar.

He found him on the watch-tower roof standing near one of the corner ribs gazing down into the encampment. Carnelian marched up to him and had opened his mouth to speak when he saw, past a winch leaning out into space, a roiling crowd below. People were streaming off the road back into the stopping place, their flight only stemmed by those already there. An incessant angry buzz mixed with the lowing of beasts. Wagons at the encampment's far edge were flattening tracks off into the hri fields. Beyond, the flat umber plain was already crawling with sartlar amidst the lazy water-wheels. 'What is happening?' he said.

Jaspar said nothing, but walking round the rib he gazed along the keel-beam, beyond the lookout in his dead-man's chair, to the south. He lifted his hand to point.

Carnelian followed the finger down the narrowing road to the tiny prong of the next watch-tower. Behind this he noticed a scribble over the dawn. He strained his eyes. 'Smoke?'

Jaspar turned to him a face the colour of the sun. 'Plague sign.'

Carnelian stood for a few moments digesting the words. Then his sight cleared and he saw Jaspar's mask and the anger seized his throat so that he could hardly speak.

'My… my Lord…'

Light slid off Jaspar's mask as it angled to one side. 'You forced my brother to come to you.' 'The creature came of its own free will.' 'You promised him he could keep his eyes.' 'Perhaps.'

'Will you honour your promise?'

'One does not consider oneself bound by anything one says to a slave.'

Carnelian fought down a desire to do violence. 'You will have your price for his eyes, I shall betray my father, but you will promise me on your blood never to touch him again.'

Jaspar's beautiful hand rose and signed elegantly, On my blood.

The Masters gathered on the watch-tower roof within the valley of its wooden ribs.

'Surely now we must go back,' said Vennel.

'We are protected,' said Aurum.

Suth had propped himself up against one of the ribs.

'Not so our servants nor the Marula,' said Carnelian, giving him an anxious glance, sickened by planning his betrayal.

'What touching concern for your inferiors, my Lord,' said Jaspar.

'In this matter each Lord must make his own choice,' said Aurum. 'I for one will go on.' He turned to Suth. 'And you, my Lord?'

For a while it seemed that Suth had not heard the question. Then he nodded. '… with you,' he said with effort.

Carnelian withered witnessing his father's worsening condition.

Then it is decided,' said Jaspar. 'We shall all go on. Unless the Ruling Lord Vennel wishes to set up palace here, by himself?'

Vennel scanned the circle of gold faces. 'No doubt nothing I can say would make my counsels prevail?'

'No doubt,' said Jaspar.

The world distorted through his tears. With the others, Carnelian had applied fresh unguent to his mask's filter. Aurum was having to threaten the Marula who eyed the distant signal with alarm. They knew how dangerous a crack it was in the sky. As they mounted, Carnelian noticed for the first time their weakness. They had a look of plants in need of water.

At the next watch-tower they all stopped in eerie silence. The air weighed down with increasing heat.

Carnelian saw his father wilt against the wall. He wanted to go to him but could not, and rationalized that it was better not to draw attention to his father's distress. When Aurum moved to support him, Carnelian felt as if he had already betrayed him. He walked his aquar towards the parapet, hunched in self-disgust. He could see the bone-white road. Travellers huddled at the margins of the stopping place or were scattered in pockets through the hri fields. Chariots and wagons were ranged like barricades. The only sound was the creaking of the water-wheels buckling in the heat shimmer as they turned.

Then they were off again. The black line in the sky split in two. Clearly, both were rising from a watch-tower Carnelian could not see. They slowed. Suth fell back so that his aquar came close to Carnelian's. He was sagging in his chair, his head resting on his chest. 'Wind your robe tight… the Black Lord's Dance.'

'Father…' Carnelian began but his father urged his aquar on and it loped forward to join Aurum up ahead.

The smoke swelled into a pair of wavering ribbons. Motes danced in the air above like swarming flies. The aquar were jogging. The Marula were cringing in their chairs. Guiding his aquar near the parapet Carnelian could see the road was no longer white, but flecked with corpses. As they continued, these dark signs of death grew denser, in places spilling off the road far out into the fields. He saw a huimur wandering, dragging a broken chariot, ploughing furrows through the dead.

Carnelian could already see the watch-tower with its horns of smoke.

'Windspeed,' cried Aurum.

They all accelerated. Remembering his father's warning, Carnelian wound himself into his cloak. This melted out some of his love for his father who, though suffering, could still care for his son.

From its upheld arms the watch-tower was pumping smoke into the sky in a roiling boil like pitch in a cauldron. They crashed over the wooden bridge. The watch-tower rushed by, its door monolith daubed with tar. The parapet opposite was set with half-charred animals skewered on poles. As these were being left behind, Carnelian realized with horror they were sartlar. His nose filter could not mask the fetor from the road. It was as if an open sewer ran below. Above, scavengers were screaming, floating on the air like ash. Fingers of plague were feeling for them across the plain. Carnelian struck his aquar to make it run faster. Other smoke columns rose off to the left wafting a sickening cooking of flesh. Along the road corpse mounds were smouldering. Hunched sartlar were building more. Mounted overseers rode through them, with whips or carrying fire. One looked up as they hurtled past. He had no face but only funereal windings of brown stained cloth.

All day they sped into the furnace south. Each changeover was made hurriedly. Slowly, the road below began to fill again with people, although only with those who were going towards Osrakum. Carnelian sank back into the chair, closed his eyes, rolled with the smooth pistoning of his aquar. The net of roads and sartlar kraals went slowly by, lulling him into a pounding stupor.

Carnelian became aware of the sun's gory eye bloodying all the clouds. Gilded land slipped past unfocused. Mounds resolved on either side of the road, defined by strokes of shadow. He began to see patterns: immense sweeping rings of red earth, straight edges, terraces. Here and there masonry looked like bone poking out of inflamed flesh. Houses, streets, a vast and ruined city. It was in a watch-tower nearby that Aurum decided they would spend the night.

Carnelian stared at his father lying on the bed. They had all crammed into his cell because he was too weak to rise.

The Marula are failing,' said Jaspar.

The poison is killing them,' said Aurum.

Vennel was rubbing his hands together. 'How can we be certain it is not the plague?'

'If it is, the boys will also be tainted,' said Jaspar.

'It might be prudent to have the boys and Marula all destroyed,' said Vennel.

Carnelian jerked round in horror.

Jaspar winked at him. 'Aesthetic perhaps, Lord Vennel, but certainly not prudent. You find me reluctant to destroy the only servants and guards that we possess. Besides, there is the practicality of whom one would use to do the destroying.'

'It will suffice that we keep them away from us,' grated Suth from the bed.