‘You are sad, Nish,’ she said softly.

‘We’ll never get out of here. We’ll never find her. I’ve failed again.’

She sat quietly beside him. Nish was touched. She cared about him.

‘I can see trees!’ called S’lound.

Nish jumped up. A scrubby patch of forest had appeared out of the foggy distance, and just as well. The reed bundles were exhausted.

It was almost dark when they landed by the forest. The following morning they chopped wood for several hours, and had a good bit stacked in the basket, when Ullii cried out.

‘What’s the matter?’ yelled Nish.

‘Someone coming.’

A tall man was advancing towards them, waving a wooden spear and shouting in an unknown dialect. There was a host of angry villagers behind him.

‘Any idea what he’s saying?’ asked Nish.

‘We’re stealing his wood.’

‘There’s wood everywhere. It’s rotting on the ground.’

‘Nonetheless, it’s his.’ S’lound sprang up on the side and began shouting back, waving a menacing broadsword. ‘Get the fire stoked up,’ he said over his shoulder.

‘We’re ready to lift.’

‘Untie the ropes.’

Nish climbed out. The balloon was already putting pressure on the knots. He got them undone but the balloon went up too fast. Afraid of being left behind, he gave a triple turn of the rope around his wrist. It tightened and jerked him up. A spear whizzed between his legs, close to parts he was particularly fond of.

Ullii gave a shrill scream. The rope felt as if it was going to tear right through his skin. If it came undone he was dead. They were already as high as the treetops.

He snatched and caught the rope with his left hand. It eased the strain a little. Then S’lound was leaning right out, hauling him up and grabbing his free hand to make sure he did not fall. Nish was pulled over the side and dumped on the floor. Ullii herself helped to bring him down, and when he lay there, gasping, she kissed him on the nose, an astonishing intimacy.

‘I can see the sea,’ S’lound said as the sun was setting.

Nish scrambled to his feet. ‘We’d better put down. We can’t afford to go over the water.’

‘Then what?’

‘We gather fuel and wait for a southerly to take us north to the mountains.’

‘Shouldn’t be too long a wait,’ said S’lound. ‘Feels like it’s blowing from the South Pole right now.’

He was still saying that a week later. This time they’d gone to see the villagers and made an arrangement with them for fuel. Nish was canny enough to pay in coppers, which they were glad to have, and the villagers chopped and fetched a mountain of wood, enough to enable them to keep the brazier going the whole time. If the air in the balloon went cold it would take hours to fill it.

The wind blew from the west, the north and even the east, but never from the south. Nish fretted. What was Tiaan up to? Ullii had sensed great urgency the last time she’d seen her. They had, however, found out where they were, somewhere between the cities of Runcil and Tatusti. Ullii had managed a clear sighting on Tiaan. Assuming she had not moved, the intersection showed her to be near Mount Tirthrax.

Late on their eighth night in that place they were woken by a great buffet on the basket. The wind whistled through the ropes, a gale carrying not snow but stinging crystals of ice. It was a howling southerly that lifted the balloon with every blast.

‘We’d better go,’ said S’lound.

‘I don’t dare take it up in this.’

‘It’ll get worse! We’ll lose it if we stay here.’

The wind screamed and flung the balloon right over. Nish thought it was going to smash against the ground. Before the craft could right itself another gust pushed it over again and the stakes on the windward side tore out.

‘Cut the ropes,’ S’lound roared, drawing his knife.

Nish did the same. Either way they were doomed. Before he could put his knife to the rope the other stakes tore free. The basket bumped along the ground. Flames belched out of the top of the brazier and he held his breath as they went close to the tarred fabric.

Bump, bump, then the basket struck an obstruction that caved in the side but kicked them into the air. They drifted sideways, almost parallel to the ground. The wind eased and the balloon pulled the basket up.

Nish climbed the ladder, hanging by one hand while he stoked the fire with as much wood as he could cram in. ‘I want to get as high as I can,’ he said when he was safely down. ‘That’s where the winds are, and the further we’re blown the less we’ll have to walk.’

Soon the brazier was glowing red, the distant ground racing by faster than it ever had. The whole balloon was shuddering, as if the air up top was moving faster than at basket level. The moon reflected silver off a thousand lakes.

‘How far to go?’ S’lound asked.

‘A hundred and twenty, maybe thirty leagues.’ Nish was watching the procession of lakes and rivers go by, comparing them with his map and making constant amendments. ‘This is a very poor chart,’ he said, peering over the side. ‘That huge lake down there isn’t even marked, and the river turns west, not east.’

‘Hard place to map, I’d reckon,’ grunted S’lound. ‘Bad maps are the soldier’s biggest problem.’

‘Except from a balloon!’ He had an idea that might earn him credit with the scrutator. ‘Hey, S’lound, what if we were to fly over all the lands where the soldiers were fighting and make proper maps from balloons?’

‘Good idea! Guess that’s why you’re in the favour of the scrutator and I’m just an old soldier.’

‘I’m not … Really?’

‘So I hear.’

‘That was before I cocked up this mission.’

‘Ain’t over yet. How long to go, do you think?’

‘At this rate we should be pretty close by lunchtime. Ah, balloons are wonderful. This trip would takes us months, through the snow.’

‘If the wind lasts. And it takes us where it wants, not where we want to go.’

‘Well, yes, but certainly closer.’

As the sun rose it reflected redly off the eastern flank of Tirthrax itself, a way to their left. They were no more than thirty leagues from the mountains, which thrust up in an east–west line from the hummocky plains.

‘Oh, this is wonderful!’ Nish cried. ‘Come look, Ullii. You’ll never see a sight like this again.’

She peeped out of the basket, earmuffed and begoggled, and even she gazed at the astounding spectacle with wonder.

‘Can you still see Tiaan? Please say that you can, Ullii.’

‘I can see her. Her crystal fills my mind.’ She pointed to Tirthrax mountain, then darted back like a rabbit down a burrow.

‘How close do you think we can get?’ said Nish. The rugged foothills would be difficult country to walk in.

‘The wind has turned more easterly,’ said S’lound. ‘It’s carrying us in the right direction, at least.’

It was the first bit of good luck they’d had on the trip. ‘And maybe it’ll turn due east when it hits the mountains,’ Nish replied.

‘Or up and over, or fling itself at the cliffs. Might be an idea to set down sooner than later.’

‘We’ll keep going as long as we can. Most of those rivers look impassable.’

They drifted towards the mountains for another couple of hours. They were still east of Tirthrax, easily recognisable because it stood a good thousand spans above any of the other peaks. Great ice mounds covered the plain below the glacier falls.

Approaching the mountain wall, the winds did blow more from the east, carrying the balloon west towards their destination. They began to encounter turbulence, which grew worse the closer they approached, flinging the balloon about until they felt seasick. Nish could hear Ullii retching in her basket but she would not come out.

He let the fire die down. They were slowly losing height as Tirthrax loomed up before them. The buffeting diminished. Another hour passed. They crossed onto the middle flank of the mountain, the tree line a long way below them.