“Uh…at ease,” he said.

“They are at ease Your Highness,” whispered Titus.

“Oh, I see. Splendid. Well, I uh… I would just like to take this opportunity to thank you all for accompanying me on so challenging a mission.”

“They don’t really have a choice,” Titus pointed out.

“They would be cast over if they didn’t accept the mission.”

“Right,” said Marcus, growing ever more self-conscious. “Um…Well, none the less, I’m encouraged by your involvement. I feel sure that if there’s even the slimmest chance my father still lives, you will be able to find him and restore him to his beloved people.”

The Cloudfarers continued to stare ahead, betraying not a flicker of response to Marcus’s words.

“Um, that’s all,” Marcus finished.

“Dismissed!” bellowed Titus.

The Cloudfarers spun round and marched towards their respective aëro:cruisers. While they did so, Marcus found himself pulled towards Asperia. Not trusting herself to master her emotions, she hugged him tightly and wordlessly, then pushed him up the gangplank of the Noble Quest.

At first it seemed as if the Noble Quest was remaining stationary while the Valorous Mission, released slightly sooner, surged up beside it. But soon the Noble Quest rose as well and the two aëro:cruisers nudged forward together. Still peering over the side, Marcus saw the landing stage slide past, severed lines coiled on it. Then the edge slipped by and there, far below, were the citadel’s walls, dropping away like gigantic, curving steps.

Marcus gasped. The walls were crowded with tiny figures, all cheering as the aëro:cruisers went by overhead. Many of them waved brightly glowing torches. After the dizzying plunge from one wall to the next, the fields and orchards rolled smoothly downward, until, at last, they merged with the fringe of the clouds, which was like the foaming crest of a wave that constantly threatened to break, but never quite did. Marcus was presented with a new, turbulent landscape of creamy peaks and shadowy troughs, passing diagonally beneath the aëro:cruiser’s bows as it set a north easterly course. Still gazing straight down, nothing below him for the first time in his life but wood braced with iron, Marcus felt instantly queasy. He stepped back and, gripping the gunnels, sought a fixed point on the horizon, as Titus had advised him to do. The experience of at last being airborne wasn’t quite what he’d expected. To the people assembled on the walls it probably appeared that the Noble Quest was moving forward perfectly smoothly. In fact it lurched up and down every few moments, as it rode the constantly changing air currents. And all the time it rose and fell it also tilted at unpredictable angles – not enough to be alarming, but just enough to be noticeable.

Breathing deeply and evenly, Marcus glanced over at Titus. The General stood with his feet planted well apart, to steady himself. Otherwise he seemed unconcerned by all the Noble Quest’s perturbing movements. With Lieutenant Rhea, his second-in-command, he held open a large chart, which flexed between them and fluttered round the edges. The two of them glanced from it to the binnacle – a low pedestal with a sloping surface that had the vessel’s compass set into it. Then Titus called out figures to the pilot, Theus, who made minor adjustments to the wheel accordingly.

Not wishing to disturb them, Marcus decided to walk to the aëro:cruiser’s stern. Titus had told him that it took everyone a while to find his air legs. He felt a little self-conscious about his unsteady gait. But as he crossed the aft deck, he passed crouching Cloudfarers who tended the valves clustered around the base of the burners. They glanced up at him curiously, but looked away the instant he met their eyes. He sighed as he climbed up to the aft’castle. Clearly it would be a while before they felt comfortable with his presence aboard.

Just a few yards away were the fringes of the orchard. Windfall fruit that had dropped from branches and rolled away before it could be picked sat rotting at their feet. Tendrils of cloud snaked upwards, curling between the tree trunks. Beyond the orchard lay the gentle slope of the fields – ploughed into fresh, glistening furrows after the harvest – then the first of the citadel's walls. Called the 'Great Wall,' it was dotted with sentinels. Their heads and torsos protruding above it, they patrolled its whole circumference, moving restlessly back and forth. Above them, the rest of Heliopolis looked magnificent, the contours of its different layers sharply defined in the high, clean air.

Concealed by the brimming ground mist, as long as they crouched, Marcus and the others continued to edge forward. Crouching was agony, since for hours already they had bowed their heads beneath the air sacs and tethered proleyne stoves to which they had been harnessed during the final stages of the ascent. But as soon as they entered the orchard they were able to drop their packs and straighten up. Every muscle Marcus possessed was aching. No matter which way he moved or which posture he assumed there was a symphony of protest from different parts of his body. There were weals on the skin under his arms too, where the straps of the harness had dug into it. The only slight respite from discomfort was provided by a breeze blowing off the cloudscape, which cooled the damp back of his tunic.

They paused again at the very edge of the orchard. By now they had definitely left the clouds behind. But, beyond the treetops, the upward slope of the fields was less clear than it had been a few moments before. A thickening haze encroached upon it. Marcus frowned questioningly at Magnis.

"More ground mist?" he asked.

Magnis shook his head.

"Too late in the day – it would have cleared up there already. No, they're burning stubble now that the harvest is over. Then they'll till the soil and re-seed it."

"Of course."

He lowered his gaze to the orchard once again. It was thickly planted and filled with webs of shadow. None the less, the sun stole in thin shafts between the branches and laid glowing coins of light on the ground.

"It's weird isn't it," he observed. "The trees got sparser and sparser then vanished altogether when we began to climb the Ins'lberg; yet here, so many miles above, there are orchards and pines and crops growing."

"Perhaps the moisture that the sun burns off the cloudscape gives them the nutrients they need," offered Rhea.

Marcus nodded.

"Perhaps."

Marcus watched them a little longer. As he did so he felt another surge of tiredness crest within him, bringing dizziness in its wake. It was so powerful it made him rock slightly on his heels. Shaking it off, he took a deep breath and said, "Well, this is it."