“That would be dangerous at this height.”

“Not if I only do it partially,” Chakkell replied, displaying knowledge he had acquired while controlling production of the migration fleet. “I can bring the ship down quite gently.”

Toller looked beyond him and in the distance saw Leddravohr in the act of commandeering the bluehorn of the officer who had rode to meet his ship. “Any landing would be gentle,” he said, “compared to the one your children would have made after falling a thousand miles.”

Chakkell shook his head. “Repetition doesn’t strengthen your case, Maraquine — it only brings to mind the fact that you were also saving your own skin. Leddravohr is now King, and my first duty is to him.”

There was a whispering sound from underfoot as the jet exhaust funnel brushed the tips of tall grass. Half-a-mile away to the east, Leddravohr was astride the bluehorn and was galloping towards the ship, followed by groups of soldiers on foot.

“And my first loyalty is towards my children,” the Princess Daseene announced unexpectedly, her head appearing above the partition of the passenger compartment. “I’ve had enough of this — and of you, Chakkell.”

With surprising agility and lack of concern for her dignity she swarmed over the gondola wall and helped Corba to follow. Unbidden, Gesalla came swiftly around the gondola on the outside and aided in the lifting of the two boys on to the ledge.

Daseene, still wearing the incongruous pearl coif like a general’s insignia, fixed her husband with an imperious stare. “You are indebted to that man for my life,” she said angrily. “If you refuse to honour the debt it can mean but one thing.”

“But.…” Chakkell clapped his brow in perplexity, then pointed at Leddravohr, who was rapidly gaining on the slow-drifting ship. “What will I say to him!”

Toller reached down into the compartment he had shared with Gesalla and retrieved his sword. “You could say I threatened you with this.”

“Are you threatening me with it?”

The sound of whipping grass became louder, and the gondola bucked slightly as the jet exhaust made a fleeting contact with the ground. Toller glanced at Leddravohr — now only two-hundred yards away and flailing the bluehorn into a wilder gallop — then shouted at Chakkell.

“For your own good — leave the ship now!”

“Something else to remember you for,” Chakkell mumbled as he let go of the rip line. He went to the side, rolled himself over on to the ledge and immediately dropped away to the ground. Daseene and the children followed him at once, one of the boys whooping with pleasurable excitement, leaving only Gesalla holding on to the rail.

“Goodbye,” Toller said.

“Goodbye, Toller.” She continued to stand at the rail, staring at him in what looked like surprise. Leddravohr was now little more than a hundred yards away and the sound of his bluehorn’s hoofbeats was growing louder by the second.

“What are you waiting for?” Toller heard his own voice cracking with urgency. “Get off the ship!”

“No — I’m going with you.” In the time it took her to utter the words Gesalla had climbed back over the rail and dropped to the gondola floor.

“What are you doing?” Every nerve in Toller’s body was screaming for him to fire the burner and try to lift the ship out of Leddravohr’s reach, but his arm muscles and hands were locked. “Have you gone crazy?”

“I think so,” Gesalla said strickenly. “It’s idiotic — but I’m going with you.”

“You’re mine, Maraquine,” Leddravohr called out in a strange fervent chant as he drew his sword. “Come to me, Maraquine.”

Almost mesmerised, Toller was tightening his grip on his own sword when Gesalla threw herself past him and dropped her full weight on to the extension lever. The burner roared at once, blasting gas into the waiting balloon. Toller silenced it by pulling the lever up, then he pushed Gesalla back against a partition.

“Thank you, but this is pointless,” he said. “Leddravohr has to be faced at some stage, and this seems to be the ordained time.”

He kissed Gesalla lightly on the forehead, turned back to the rail and locked eyes with Leddravohr, who was on a level with him and now only a dozen yards away. Leddravohr, apparently sensing his change of heart, struck his smile into existence. Toller felt the first stirrings of a shameful excitement, a yearning to have everything settled with Leddravohr once and for all, regardless of the outcome, to know for certain if.…

His sequence of thought was broken as he saw an abrupt change of expression on Leddravohr’s face. There was sudden alarm there, and the prince was no longer looking directly at him. Toller swung round and saw that Gesalla was holding the butt of one of the ship’s ptertha cannon. She had already driven home the firing pin and was aiming the weapon at Leddravohr. Before Toller could react the cannon fired. The projectile was a central blur in a spray of glass fragments, spreading its arms as it flew.

Leddravohr twisted away from it successfully, pulling his mount off course, but shards of glass pocked his face with crimson. He gasped with shock and hauled the galloping bluehorn back into line, rapidly making up lost ground.

Staring frozenly at Leddravohr, knowing the rules of their private war had been changed, Toller fired the burner. The skyship had been made lighter by the departure of Chakkell and his family and had been disposed to rise ever since, but the inertia of the tons of gas inside the balloon made it nightmarishly slow to respond. Toller kept the burner roaring and the gondola began to lift clear of the grass, Leddravohr was now almost within reach and was raising himself in the stirrups. His eyes glared insanely at Toller from a mask of blood.

Is he mad enough to try leaping on to the gondola? Toller wondered. Does he want to meet the point of my sword?

In the next pounding second Toller became aware that Gesalla had darted around behind him and was at the other cannon on the windward side. Leddravohr saw her, drew back his arm and hurled his sword.

Toller gave a warning cry, but the sword had not been aimed at a human target. It arced high above him and sank to the hilt in a lower panel of the balloon. The fabric split and the sword fell clear, spinning down into the grass. Leddravohr reined his bluehorn to a halt, jumped down and retrieved the black blade. He remounted immediately and spurred the bluehorn forward, but he was no longer overtaking the ship, being content to pace it at a distance. Gesalla fired the second cannon, but the projectile plunged harmlessly into the grass well clear of Leddravohr, who responded with a courtly wave of his arm.

Still firing the burner, Toller looked up and saw that the rent in the varnished linen of the envelope had run the full length of the panel. The edges of it were pursed, invisibly spewing gas, but the ship had finally gained some upward momentum and was continuing its sluggish climb.

Toller was startled by the sound of hoarse shouting from close by. He spun round and discovered that, while all his attention had been concentrated on Leddravohr, the ship had been drifting directly towards a scattered band of soldiers. The gondola sailed over them with only a few feet to spare and they began to run along behind and below it, leaping in their efforts to grab hold of the ledge.

Their faces were anxious rather than hostile, and it came to Toller that they had only the vaguest idea of what had been happening. Praying he would not have to take action against any of them, he kept on blasting gas into the balloon and was rewarded by an agonisingly slow but steady gain in height.

“Can the ship fly?” Gesalla came to his side, straining to make herself heard above the roar of the burner. “Are we safe?”

“The ship can fly — after a fashion,” Toller said, choosing to ignore her second question. “Why did you do it, Gesalla?”