He followed Keal up the stairway. When he reached the top, he closed his eyes, sucked some deep breaths through the mouth of his mask, then stepped out onto the deck.

Slaves were scrubbing the grating. A path through the blood had already been cleaned from the stairway to the prow. There Carnelian saw the huge rectangle of his father's back among the smaller shapes of their guardsmen. Carnelian followed Keal along the path. His father turned as they approached. His mask lent him a cruel look. He moved to one side and the guardsmen cleared a way. 'Come, stand beside me, my Lord.'

Carnelian moved into the space and immediately their men formed a wall of screens that separated them from the rest of the ship. His father reached up to unfasten his mask. Carnelian's hand shook as he was forced by protocol to do the same.

His father's grey eyes fell on him. 'How are you feeling, my son?'

Carnelian forced back the tears. He was no longer a child.

Suth reached out and touched Carnelian's cheek. 'You will have to get used to death. Perhaps I have erred to keep you so shielded from it these long years. The Chosen are great dealers in death. You would have found this out in Osrakum had you been raised there. I fear you have acquired an unnatural sensitivity to it.'

Suth looked out across the sea. Carnelian followed his gaze. He let the strain out and it saddened his face. A blue wall of cliffs had risen before them that edged the whole horizon. The wind washed him. It squeezed some tears out of the corners of his eyes and ran them back along his head to his ears.

'Behold,' said Suth. He was careful not to look at his son lest he should weaken the boy's self-control. 'Behold the shore of the province of Naralan, the edge of the Three Lands.' He shook his head slowly as if he did not believe what he saw. 'Once you set foot upon her brim, Carnelian, your life will be forever changed. You cannot know, my son, who and what you are. It is not your fault. It will come slowly at first. You will see such beauty, and such terror, but the wonders.' He sighed the last word. 'Such wonders as not even your mind's eye has beheld.'

He dared to look at his son. He had sensed that his words were soothing the boy. 'But though you shall acquire the freedom and the thrill of power you shall always be restricted by the Law-that-must-be-obeyed. Today's bloody lesson you will not soon forget.'

He waited for a reaction but his son merely nodded. He continued, 'Duality is the essence of creation. As certainly as night follows day, all gain is balanced with loss.

'Now, listen. There is a perilous game. The Law forms the matrix in which it is played. The Emperor, the Great and the Wise are its players. We must all play. I have almost forgotten how to. My moves are unsure, but it is coming back to me. You too must learn to play. There are such forces ranged against us…'

Carnelian had at first been glad of the distraction of politics but now he felt as if a shadow was being cast over them.

His father made a sign of dismissal. 'Still, by the grace of the Two we shall yet prevail. Remember the warnings I have given you. All is not always as it seems. A knife is often concealed behind a smile.' He looked back towards the cliffs. Suddenly he lunged forward, bracing himself on one of the curving horns of the prow figurehead. He was searching the sea before them. 'Look,' he cried and pointed.

Carnelian leant out and saw the shadow in the sea moving ahead of them. 'A turtle,' he said. The creature must have been as big as the ship. Its vast oval wavered just under the water. Its paddles rowed like huge oars. The Wise taught that the world had been made from the dismembering of the Lord Turtle. His eyes had become the sun and moon. His carapace formed into the firmament of the sky. His flesh was the earth that floated on the sea. All life had sprung from his blood. Now, that ran pure only in the veins of the God Emperor, and in Carnelian's own veins, as in those of the other Chosen, tainted by mortality.

They watched the turtle veer away. 'For a moment it was guiding us home. Creation through sacrifice,' his father said. The best of omens.'

Creation through blood sacrifice. Behind him, Carnelian could hear the slaves' brushes rasping at the deck. Was it not also an omen that his first sight of the Three Lands should be an occasion of massacre?

'See there,' his father said. He pointed off across the starboard bow to where a narrow feather of smoke seemed pinned to the cliff wall. That is the Jamb Rock where a fire burns night and day to guide ships into the Grand Harbour of Thuyakalrul. Do you see that lower, darker band of cliff that spreads on either side of the beacon? Well, that is the outer wall of the harbour. Thuyakalrul is well named; she is indeed a ring of blue stone lying in the sea. Within her circle lies the harbour. It has but a single door, a breach in the northern curve of the ring. The town itself is set into a depression in the southern wall. From there a causeway crosses a lagoon to the mainland and the road climbs a valley up to join the Great Sea Road.'

'And that road leads eventually to Osrakum,' said Carnelian.

Suth almost sighed with relief as he saw the colour come back into his son's face.

'But if all this is so, my Lord, why then do we not sail directly towards the beacon?'

Suth smiled. 'Because, my son, Thuyakalrul is ringed about by another yet greater wall and even now we seek one of its gates.'

'My Lord speaks in riddles.'

From the stern they heard the captain barking commands.

'You shall see soon enough, but first we should remask.'

They did so, and then his father dissolved the wall of screens. Keal was there with the others. He shot Carnelian a look of sympathy. In the rigging slaves were closing up the fan-sails. Under the curving fish-tail of the stern, the captain stood between the two steersmen with their oars. He said something to the man standing behind him. The man operated one of the levers set into the stern post, and in response the pounding of the drum slowed to breathing pace. The threshing of the oars slowed. The wind fell and with it their cloaks which had been surfing on it. The captain spoke to another man and pointed up the ship. There was an argument as the other man refused to do what he was told. The captain shoved him out of his way and then came forward himself. 'Now you shall see,' said Suth.

The captain came closer. Carnelian saw the twitch in the man's eyes, his mouth pinching into a quivering smile. The man fell to his knees and did not move.

'Up, man, up. Get on with your business.'

The captain's face came up gaunt. He rubbed his mouth with his hand. Muttering something he crept past them, nodded unconsciously to the altar of the Gods and then went to the starboard bow. He scanned the water ahead. Carnelian leant on the rail to see what it was he sought. He noticed a darkening in the sea in front of them. The captain looked back anxiously and shouted something. The steersmen leaned on their oars. The ship turned her head slowly in response. The bruising in the water rushed towards them.

'A wall under the sea,' gasped Carnelian.

'Even when it is submerged, few channels lead through it and only one is deep enough to allow the passage of a baran,' his father said.

The captain kept whisking round to shout frantic commands. Then the black water was upon them. The ship jolted as if she had hit something and then the blackness was pouring past them.

'How do they find it?' Carnelian asked, amazed.

His father pointed to where Carnelian could see a tiny spine jutting up from the cliff. Then he pointed back the way they had come. A crooked bronze post rose out of the sea. The post and the cliff tower in a line will bring a baran safely through the reef.'

Other posts went past like green men standing on the waves, pointing out the way. In some places the reef came up almost into the air. Sinuous filaments of light quivered over it. At the captain's cries the steersmen nudged the ship first one way then the other. At last she was through into the green water beyond. The captain passed them and jerked a bow before rushing back to the stern.