"What are you doing?" Inata asked.
"A kite wing," her brother replied.
"This is no time to play around! I thought you agreed we should try to get back to the centre of the disc as quickly as possible."
"That's exactly what I'm doing. Haven't you ever heard of kitesurfing?"
"No, what's that?"
"It's a sport, somewhere between paragliding and windsurfing, where people get pulled across the water by a giant kite sail."
"May I remind you that we were born in the middle of a forest and have never seen the sea, you triple idiot."
"That doesn't stop anyone from reading and educating themselves about the world, miss."
"Yes, and what does that have to do with getting back to the centre of the disc? Do you see a lake around here?!"
"No, but who told you we were going to glide over water? We're going to glide over the air, just like you showed we could do to stretch out the time of our leaps."
"Yeah... I don't know if you noticed, but the wind blows from the centre toward the outside of the disc. That's what they call centrifugal force, mister well-read who forgets essential details."
"Let me point out that there is a concept you don't seem to know, and it's called sailing upwind. Sailboats can go in directions other than the wind's. It's called tacking. It's all a matter of vectors. You'll understand that too when you're as good at maths as I am. That's exactly what we're going to do."
Despite his sister's doubts, Hichy devoted all his time to crafting the sail they needed. Melio liked to nap at his feet while he assembled the different materials. He made ropes out of plant fibres, braiding them together one by one. The work was long and tedious, but Inata, having no better idea to suggest and unable though she was to understand exactly what her brother was aiming at, helped him as much as she could.
As for the sailcloth, he would have liked to make it out of linen. Even with all the powers in the world, weaving still required skills he did not possess. Besides, building a loom, with steel needles and complex mechanisms, would have taken him years. So he made it out of leaves instead. The whole thing was certainly less sturdy, but it should be enough.
Two weeks later, on a day when a light breeze had begun to blow above the trees, the boy was finally able to test his traction wing. He leapt into the sky holding it under one arm and deployed it as high as possible. Then he landed on a little carpet of air and filled the sail in the sky. His feet began to skid, so he quickly realised he would not be able to do without a real board to surf on the air. His shoes needed to be strapped down, and sailing upwind required pushing back against the direction of the moving air masses with a centreboard and a fin.
With his board, Hichy's second attempt was far more convincing. He managed, more or less, to control the direction in which he wanted to go and made several back-and-forth passes above the treetops, with the kite serving both to move him forward and keep him aloft.
Since the strength of his arms alone was not enough, he made a harness to pull on the wooden bar attached to the sail lines. He improved with every new attempt, and if his sister had not reminded him of the goal of their quest, he might have kept gliding through the air for hours, just as windsurfers spend entire days sailing and surfers playing with the waves.
"Aren't you tired of clowning around yet?" Inata asked as her brother landed gently near their camp.
"Wow! That was amazing! I made a fantastic leap and..."
"Oh, enough already! I think that's enough now, and it's time to go."
They had no need to pack, since they no longer owned anything, and decided to leave the very next morning. The three of them leapt into the air and strapped themselves to the surfboard, Inata sitting behind her brother and fastened securely in place. She held Melio in her arms with all her strength despite his protests, his claws, and his bites. For extra safety, Hichy had tied the animal to the end of a rope leash. The boy deployed the wing in the air after firmly securing his feet in the straps. Standing at the front, he bore the heavy responsibility of bringing everyone safely through.
Although the weight was greater than when he was alone, he managed to keep them aloft. With the winds in their favour, they quickly approached the much-feared cylinder. When they drew near, the sail suddenly collapsed under the effect of an adverse wind shift. They lost a hundred metres of altitude at once before cushioning their fall on a carpet of air. Hichy nevertheless managed to fill the wing again as it twisted wildly in every direction. The gusts grew stronger and stronger as they entered the turbulence zone surrounding the disc.
Then the sail gave them a sudden violent tug, and they had to cling on with all their strength to avoid being swept away. They had just crossed the belt of debris and entered the vortex. The ropes screamed under the dreadful tension pulling at them, and Melio's fur stood on end, the little ginger cat clearly not being especially fond of aerial sports.
"It's going to snap!" Inata cried in alarm.
"Of course not!" her brother replied, though he was far from reassured.
Though the ground was racing beneath them at an incredible speed, it was doing so in a circle. Their progress toward the centre of the disc, on the other hand, was maddeningly slow. Melio kept meowing in protest, and Inata clung on with all her might so as not to be thrown off. The twin's feet sank down to his ankles in the straps as he fought not to let go of the sail.
Only after two full revolutions, corresponding to four hours, did the pressure finally begin to ease a little. Hichy's arms were completely numb despite the harness. Though she had remained seated, his sister was also exhausted. Melio was no longer even struggling, which was more worrying than seeing him bite at his bonds. Several ropes had snapped, but the wing was now perfectly stable and full.
"The closer we get to the centre, the weaker the kinetic force becomes," the boy explained.
"That much I know, idiot," his sister scoffed.
"The weaker the wind gets, the slower we move."
The wind did indeed keep dropping little by little until, two more revolutions later, it became too weak to carry them above the trees, and the harness became useless. They glided for a long while before landing very gently among the trees.
"And now?" Inata asked.
"Now we rest a bit before setting off again," her brother replied, collapsing onto the ground.
"Do you think we're far from the centre?"
"I don't think so. The effect of centrifugal force is barely noticeable."
"Look at the leaves. They're starting to brown. And the sun is setting earlier and earlier."
Without a lighter to start a fire, the twins had trouble warming themselves. In books, all you have to do is strike two stones together or spin a piece of wood between your palms to make sparks. In real life, theoretical knowledge is not enough, and hours of practice are required. Very conceited is the person who believes they can instantly reproduce what the first humans took millions of years to discover.
Hichy crafted a hut covered in a thick layer of moss and foliage while his sister went looking for a few mushrooms. Melio was delighting in devouring raw field mice while the children's stomachs cried out with hunger.
"We absolutely have to warm up and eat properly before we go on," the boy said. "I'm going to look for sulfur crystals," he declared. "In the meantime, make us some clothes as best you can."
"And why should I be the one doing the sewing while you handle the fire?!" the girl protested. "We're not living in the Stone Age anymore, if you hadn't noticed."
"You can be so annoying! And why should we automatically do the opposite? I'm sure you would have complained if I'd suggested I make us clothes while you looked for a way to start a fire."
"Actually, I have one. It's easy, look."
Inata picked up a piece of green wood and, thanks to her magic, had no trouble extracting almost all of the water molecules from it. The branch became as dry as if it had lain for years beneath the sun in a sand desert. Then she did the same with a strip of bark and, as she had seen in the illustrations in her books, she spun the piece of wood between her palms. She gathered some grass and twigs, which she had also dried beforehand, and flames soon sprang up before them.
"That's cheating!" the twin pointed out.
"So what? It's less cheating than using a lighter. And now, who's going to do some lovely sewing for his adored sister?"
Hichy pulled a face. If he hadn't managed to weave linen, he was hardly going to make a cotton shirt. He had secretly hoped his sister would be more gifted than he was in that regard, but he had no idea how to solve the problem.
"Fur!" Inata suddenly cried.
"Huh?"
"Fur. That's the only thing that'll keep us warm. Remember when you made a pillow out of all the hair Melio left on the brush? All animals shed fur, by rubbing against trees and naturally too."
"I hadn't thought of that."
"That's because you're not as smart as I am, you triple idiot."
Hichy took a deep sniff of his four-legged companion's coat to identify its structure. In less than an hour, he managed to gather bristles from boars, martens, wolves, weasels, as well as fur from field mice and rats. He started by making a hat, sticking it with sap onto a straw framework.
"Ugh! That's hideous!" his twin mocked.
"We're not in a fashion contest. I'd rather be ugly and warm than handsome and cold."
"Don't worry, the second option is impossible."
"Brat!"
"Idiot!"
With full stomachs and clothed in garments as ugly as they were comfortable, the twins fell asleep happy to have bickered. In only a few days, they would reach the centre of the disc, if all went well.