He jumped. Their Sinistral guide had returned. The gloom between two towers was dewing more of his kind. Some were carrying chairs, one of which they settled on the floor beside Carnelian. He sat himself upon it and was lifted up beside Jaspar. Trailing the latter's people, they marched into the column forest.

Craning round, Carnelian soon lost sight of the tunnel mouth. For a while he could still catch snatches of the dark outer slope that walled off the Plain of Thrones. Then the chair leaned forward and he had to brace himself against its footboard. Past the two files of their left-tattooed heads he saw the steps his bearers were descending; the towers' roots formed buttresses on either side. Between their trunks he glimpsed meandering avenues, or he found himself looking up into valleys from which paths and stairs came tumbling like streams. Leaning his head back he saw a flock of birds flying their tiny crosses against the vaulting. The faces up there awed him with their disdain, causing his eyes to drop, forcing him back to his proper level at their feet. Their presence pressed down like the unbearable anticipation of thunder from a stormy sky. This was a place where mortals must creep or else be trampled underfoot. This was the Gods' sepulchre. The deathly stillness was making the air too heavy to breathe. Wherever he looked, constantly shifting perspectives ensnared his eyes. When he tried to escape by closing them, the rise and fall, the shifting angle of the chair, made him seem always on the edge of falling.

Deeper and deeper they wound their way into that forest of the night. It was an underworld meagrely lit by a rind of moon he searched for but could not find. They came into a region where the Gods were reflected in a black tarn. Once, he was sure he spied through a faraway edge of the forest the Yden: an alluring string of slivered emeralds hanging in the gloom. Lost in the terrible twilight, Carnelian found it harder and harder to believe that he had ever been anywhere else. Only the rasping rhythm of his bearers' breathing, and the sight of Jaspar's chair, reminded him of who and where he was. Then, for moments at a time, he was able to cling to the faith that one day they might find their way back into the living world above.

Miraculous light was seeping towards Carnelian through the trees. He could hardly believe that it might be the forest's end. As it grew brighter he looked around him as if he were coming awake. The trunks' grooved drapery folds reminded him that they were not trees but gods, and then only gods of carved stone. As they passed between the last of them into the clearing, the nightmare was already lifting.

His chair stopped, suddenly, shockingly. He had learned to know all its rhythms save stillness. Half-black faces looking back past him made him crane round. Stooping, Jaspar's people were stumbling out from the columns that faded away behind them into impenetrable darkness. 'Just a cave,' Carnelian said, but his shudder betrayed the lie.

Jaspar came alive in his chair. 'My… Lord… cousin?'

Carnelian focused on the Master. The Labyrinth… it is only a cave.' He tried to force conviction into his voice.

Jaspar's mask stared at him for some moments before turning away. The stair.' His voice sounded dreamy.

Carnelian looked and was crushed as if the green cliff rising all around them were a tidal wave of water.

The Pillar… of course,' he muttered, daring to lift his eyes.

They were in a fissure of the Pillar rock that opened raggedly to the north-west. Up it funnelled, shadow-mottled, filled with heads and limbs. The fissure was all carved. His eyes floated higher and higher. The rock turned black but still it climbed and Carnelian's eyes could find no end to it. He gaped, stunned. This mountain dwarfed even the cliff edge of the Guarded Land, yet it was carved all the way to the sky.

The Rainbow Stair,' said Jaspar.

Carnelian's eyes came clambering back down the crags. They took a while to grow accustomed to the nearer scales. He could see nothing like steps, only, in the shadows, rills of water winding down among the mossy men. The ground was sodden, with a road crossing it. He narrowed his eyes to look out through the fissure's open side. He blinked several times. The stone forest of the Labyrinth fell away down a slope till over its green undulating roof he could see the Yden's melting emerald spreading out to meet the Skymere. His gaze crossed the causeway to where the wedge of the Valley of the Gate was cut into the girding mass of the Sacred Wall.

'We have waited for them long enough!' cried Jaspar, his anger stinging their chairs into movement.

Carnelian hung over his chair's arm, reluctant to disengage his eyes from the glorious vision of the crater. After the Labyrinth its airy freedom was a salve for his eyes. The mouldy smell of the Pillar's stone drew him back to the creatures that lurked in it. Like ferns, they grew up from the boggy earth, uncurling their limbs and smiles over the heart-stone. He saw the stair. Steps, striped with red chalcedony and amber, gold, jade, turquoise and lapis blue, and, where they touched the Pillar's wall, bordered by a band of amethyst. Among the green spiralled men, the stair's rainbow ribbon climbed as far as he could see.

They climbed the Rainbow Stair into the sky. The Labyrinth's roof stretched below as a vast scrubby plain merging its edge into the emeralds of the Yden. Beyond was the blinding blue of the Skymere. Humid air rose carrying hints of perfume that mixed with the wafting sweating of the bearers. The sun's heat was terrible. Carnelian was glad of the cowl of his robe.

The stair darned its way back and forth across the fissure. They kept to the red and amber bands so that if on one flight they were walking close to the fissure's carved wall, on the next they would be at the stair's edge where Carnelian would be able to see down the great fall to the ground. Parties of ammonites and Sinistrals passed them, returning to earth.

When the floor of the fissure looked the size of a shield, doorways began appearing among the carved men. The rock became riddled with windows, with stairs as steep as ladders. Hanging banners proclaimed the presence of Masters whose retainers were huddled up the steps. Tattooed faces turned to watch them pass as Jaspar's party picked its way through them.

They came to a long landing. On one side the Pillar's rock rose carved with avatars and balconies, all pierced with doors and windows. On the other a narrow pool ran alongside the rainbow paving. Here Jaspar had his chair put down and Carnelian, observing him climbing out, took the chance himself of stretching his legs.

The pool ruffled with sunlight. Its furthest edge was a bone of rock beyond which was the vast fall. Carnelian saw that Jaspar's people were hoisting chests up a stair to one of the apartments cut into the cliff. Two of them were feeding an Imago dragonfly banner over a balcony.

Carnelian went up to Jaspar. 'Are you planning to stay here?'

This is as good a halfway house as any to spend the night.'

The night?'

Jaspar's mask regarded Carnelian with contempt. He sighed. 'It is customary to spread one's journey up the stair over two days.'

'Why?'

'Because, my Lord, otherwise one can be afflicted by the sky sickness.' 'My Lord?'

Jaspar looked up and his mask mirrored the sheer cliff of the Pillar they still had to climb. 'Up there one breathes the sky. Even the Chosen must accustom themselves gradually to such purity.'

Carnelian gazed. The mountain was lodged like a thorn in the infinite depths of the heavens. 'One recovers from this sky sickness?'

'In time.'

'A day or two?'

Jaspar's hands made a gesture of exasperation. 'Sometimes three.'

'I am young, my Lord, I will take the hazard. I intend to see my father today.'