Nish looked at Ullii. ‘Well, at least we’re alive.’

‘I knew we’d be all right,’ she said.

The climb down was unpleasant. Though Nish was not afraid of heights, the knife wound troubled him and Ullii did not seem to understand how high they were, or how to get down. The branches were spaced uncomfortably far apart and she had no idea which ones would support her weight and which would not. He had to check her every step, as if she were a two-year-old.

Eventually they did reach the ground, where he was at a loss what to do. The black balloon could be seen for leagues and he was tempted to burn it to make it harder for the enemy to find them. Of course, he could only do that from underneath the tar-soaked fabric. Besides, a fire in the treetops would be even more visible.

Nish did not think there was any possibility of repairing the balloon, which was a pity. He could see no other way out of here. There had been no sign of habitation from above and they would soon starve to death in this wilderness.

His side began to ache. Taking off his jacket, jerkin and bloody shirt, he inspected the self-inflicted injury. A long shallow cut ran up his ribs almost to his armpit. The wound had closed over but was rather painful. It was getting late. Having no idea what to do, he put the decision off until the morning.

‘We’ll have to camp here.’ He unpacked the tent. ‘Could you find some firewood please, Ullii?’

She stared blankly at him.

Nish suppressed the urge to slap her. Ullii had never learned to do the least thing for herself and had no concept of cooperative labour. That was just the way she was. She was not going to change.

‘We must have a fire, Ullii,’ he said patiently, ‘and I’ve got to put the tent up. Could you collect some wood, please?’

He pointed to a branch on the ground. She tried to pick it up, found it was too heavy and just stood there looking at it. Sighing heavily, Nish showed her two others that she would be able to carry. By the time he had erected the tent, she had brought back the two pieces of wood and was squatting by them, shivering.

‘That’s not enough, Ullii. We’ll need ten times that much to get us through the night.’

He had to show her, piece by piece, and then help her to bring them back, so he might as well have done the work himself. Finally, when the fire was blazing, Nish looked around for the dinner bag. It was still in the basket at the top of the tree, with their packs.

It was getting dark but they had to have food. The climb, a good thirty spans up, then down again in the gloom, was not one he cared to think about afterwards. But he made it with no more damage than a lot of skin off his hands and the departure of what remained of his temper.

‘I’ll make the dinner, Ullii …’ He was speaking to empty air.

Nish swore. Where had the wretched woman gotten to? About to roar out her name, he heard a gentle snore coming from the tent. Ullii was inside, curled up in his sleeping pouch, fast asleep.

‘All the more dinner for me,’ he said selfishly, and set to with the frying-pan.

On the morning after the crash, Nish discovered that the minor injury, which he had been too weary to tend the previous night, had become infected. It was now an angry red from one end to the other.

‘This is all I need,’ he muttered, peeling off his shirt.

‘Don’t die, Nish,’ Ullii wailed, thrusting her head hard against the wound.

It was agony. Nish cried out and shoved her away, biting back tears. Ullii put her hands over her ears and ran into the forest.

‘Come back,’ he yelled once the shooting spasms had eased. She did not answer. Well, let her go; she would not run far.

He boiled water, cleaned the wound, then put on salve from the medicine kit and bound it up in the cleanest cloth he had. With the rest of the water, Nish made a brew of liquorice tea, sweetened with great quantities of honey from a comb. The tea was too hot to drink, so he leaned back against the tree and closed his eyes, the better to think.

The balloon carried a small repair kit: needles, thread, a length of silk cloth and a pot of tar to seal it with, though Nish doubted if there was enough fabric for this job. The tear was long, with subsidiary rips radiating out as far as the seams in the material. Without them the top of the balloon would have torn off.

Still, he had to try: the idea of walking out of here was laughable. He had already consulted the map which, even if it was accurate, showed no town within ten leagues. Ten leagues of frozen waste that was rapidly unfreezing, turning even small streams into impassable barriers.

He could, he supposed, attempt to build a raft of logs tied together with the ropes from the balloon. That would be easy enough for someone with his artificer’s skills, and he had an axe. As long as the green wood floated. But rafts were difficult to steer and at the first set of rapids it would be torn to pieces, dumping him, Ullii and everything they owned into the icy water where, if they survived the rocks, they would quickly drown or freeze to death on the shore.

Repairing the balloon was the better gamble, and he’d better get started. Leaving Ullii to return in her own time, Nish shinned up the tree next to the one they had landed in, so as to gauge the repair job. He was inured to the climb now, though his wound hurt more than before. At the top he took a firm grip on the trunk and leaned out. He was level with the top of the balloon, which was sheltered from the wind by the surrounding treetops. The damage was worse than he had expected, the main tear a good three spans long. How could he possibly repair that?

On the ground again, he found Ullii in the tent, curled up into a ball, but he was sure she was awake. He did not go in, just made sure she knew he was there, and in sound health.

He spent the rest of the day by the fire, considering possiilities for repairing the balloon, and rejecting them all. The infection grew more painful and, by the afternoon, climbing the tree was impossible. He went to his sleeping pouch as soon as the short day ended.

For the next three days, snow fell lightly all day and wind whistled through the branches. It was too cold to risk exposure up in the trees, for he could not work bundled up in his cold-weather gear. He spent the time carving and shaping pieces of wood with the blade of his axe and the tip of his sword. It was awkward work. The time dragged, the only comfort being that the lyrinx did not come back. Nish saw them wheeling in the air on occasion, in the direction of the mountains, and wondered what they were up to.

One day, trudging down to the river for water, he saw a white shadow thumping the water with a flat paddle, making a booming sound that could have been heard half a league away. Nish slipped behind a tree. It was a great Hürn bear, scarcely visible in its shaggy winter coat. It was in the water now, scooping stunned fish out onto the bank. A magnificent animal, this one was bigger than a lyrinx.

As he watched, its head turned in his direction. Nish went still. Hürn bears were not vicious but they were territorial, and even a backhanded blow from those paws would be the end of him. As soon as it went back to its fishing, he slipped away to the camp. He and Ullii spent a cold and uncomfortable night halfway up the tree. Nish did not sleep. A Hürn bear could climb better than he could.

On the following morning he woke to feel no pain in his side, just the tightness of healing flesh. The sun was out, already melting the snow on the branches. He went up at once. Though they had plenty of food, the supply was not inexhaustible and every day they stayed here increased the risk of lyrinx coming to investigate. Or Hürn bears.

He assembled the shaped pieces of wood into a small block and tackle. Passing the rope through it, he tied one end to the tree and tossed the other across to the neighbouring trunk. Climbing down, then up, he passed the rope around the trunk and threw it back to the first.