Tickets for the train. Neither of them thought about they would need tickets! The twin fell into despair again, but this time, they didn't cry. They have learned, that they just had to find out how to get those tickets.
"No, we don't have tickets." Valerie admitted.
"How could we get tickets?", asked Conrad.
"Buy them."
"How much does a ticket cost?"
K.O. told them. The twins silenced. The sum was huge. They couldn't afford them. Well, basically, they couldn't afford anything to buy, because they didn't have a single coin. The only thing they had, the clothes, they wore.
"Probably, your grandpa will get you tickets back home." K.O. tried to console the kids. "But first of all, you have to find him."
"What if we never find him?", asked the embittered girl.
"I think you could do the same thing: you have to work."
The kids nodded. It was the only solution for them. They needed money to find their grandpa, and they also needed money to travel home, if they couldn't find him. Money comes from work, so their only choice was working to get money. Fortunately K.O. gave them work: the field, designated for him is needed to be harvested. It wasn't a difficult work, and after the twins accepted their situation, the harvest became really funny. Valerie and Conrad started to compete, which one of them had been collected more Hydrogen. Just like in a game, so the twins clearly enjoyed the work.
There was one more really funny thing. The more Hydrogen they collected, the top of the car was more and more inflated. It soon looked like an out-of-shape balloon, which slowly but surely inflating to the right shape. The fabric of the top of the van was made of a special material, to prevent Hydrogen to escape. Although it was old. It had a big, yellow patch on the side of the flower-shaped body of the balloon. The tiny ones were always playing, jumping, kicking in the side, and K.O. noticed, that he should change the balloon, before the tiny ones would kick themselves out, and he would have to chase them in the fields. They could run really fast, after pairing.
Having a big balloon on the top, the van also started floating. It was funny at first, as the wheels of the vehicle was a few centimeters above the ground, and the twins could push the whole, heavy car with ease. They were spending a little time toying with the car, and they just regretted not having a phone with them to make a video of it. As the balloon was inflating, the gap grew between the wheels and the ground, so getting into the van became inconvenient. They had to jump to the first step, and pull themselves with their arms to reach the door. Valerie and Conrad were soon regretting to relax in the physical education classes. When the gap became bigger, than the kids could jump, K.O. pulled out an old anchor and fixed the car to the ground.
During the work somewhere, somehow K.O. and the kids became friends. They were talking a lot, and the old man was full of interesting stories, good advice, and tips for the twins. Valerie and Conrad were learning fast and enjoyed the stories of the old man. They had known, that the fields are belong to the Kingdom of Hydrogen. The kingdom had a capital, where they could have found the railway station, a center, where all the works were listed on a blackboard, so they could choose which work they want to do. There were ways to reach other kingdoms, where beautiful beaches, skyscrapers, old-fashioned towns and greenery were also exist. There were a big mountain, where top secret projects were doing, so they should avoid that place. But works were available anywhere else.
"By the way! You should buy a hand device first, before you accept a job." He told them in one of the intervals.
"Hand device?"
"Like this one."
K.O. showed them a rectangle-shaped device, which had a lot of buttons on the sides, and a cell phone - like display on the front. It had a phone holder on the back.
"It is from a real cell phone." K.O. laughed, when the twins mentioned the similarity for him. "It is useful to hold it with one hand and deal with these little one with the other. But it is more than a cell phone. The basic device is for collecting energy bars and candies, counting and storing your money, and you could use it for paying. There are a lot of extras, you could buy for the device, but I don't think so you would really need more."
"What kind of extras?", ask the kids with shining eyes. This was very similar to the normal cellphones, therefore it was something familiar.
"I don't mean these extras are some kind of games!" K.O. warned them, suppressing his smile. "But you will see one of the extras tomorrow."
"Show it now! Please!"
K.O. shook his head, and pulled the goggles to his eyes. He looked around slowly.
"It is getting darker in the intervals, have you noticed?"
The twins nodded.
"It means the field will soon exhaust. Maybe two or three waves of birth are ahead."
"What will we do then?", asked Conrad. He was worried. What will they do, when the harvest ends?
"We will be sorting the little ones!" K.O. grinned at them. "That will be a heavy task, so now let's go and get some good sleep!"
K.O. was right. The next day the harvest was short, and the darkness was growing. The light, which the Hydrogen produced before born was decreased, so they hardly see each other. K.O. was smiling mysteriously, when the twins complained about the darkness, and disappeared inside the car.
"Another one!" Valerie cried, as she noticed the cracks on the ground, but Conrad was quicker, and he could catch the next one first.
"It is a strange one!", he told his sister in a big surprise, after he examined the little one.
The little one, he caught, was alone, and silent. They were so used to the crying of the lonely Hydrogen, that it was really surprising. It was a little bit bigger, than the others, and it had two arms. The hands were holding each other, and the tiny one were peacefully watching the twins.
"K.O.!" The kids were crying instead of the little one. "We have found something strange!"
"Hohohohoo!" He came back, and patted the little one. The sphere were chirping cheerfully. "You overthought a little, didn't you?"
"Overthought? We just collected it, without thinking!"
"I don't mean you! It is the Hydrogen, who overthought! Wait a minute!" He went back to the car, and a minute later he returned with an old fashioned oil lamp, emitting a green light in one hand, and a pair of Hydrogens in the other.
"I hope, we have luck! Hold it for a while!", he said, and gave the pair to Valerie.
The green light illuminated them and their surroundings beautifully. The kids were surprised to notice that Hydrogens were bouncing in the lamp, and they were the ones who were glowing green.
"Are you curious?"
The kids were so immersed in their thoughts, that they couldn't even nod. They were helplessly watching the different little ones. K.O. took out his hand device and pulled out one of the buttons.
"These little ones are different not just outside, but inside too! Look!"
He put the button to the head of the little one in Conrad's hand. The twins leaned over the tiny screen. It showed little spheres inside the little one. Two of them were gray, the other two were red, with a cross on them. K.O. moved the button to the Hydrogen in Valerie's hand. Inside one of the little one there was only one red sphere with a cross on it. The other had a gray and a red sphere. In the end the old man put the button to one of the Hydrogens in the lamp. That one had two gray spheres beside the red one.
"Have you seen the difference?"
The twins nodded.
"Why are they different?" Valerie asked first. "I mean Hydrogens are not different in the outside, but different in the inside! Are they really all Hydrogens?"
"They are all Hydrogens and yet they are not."
Their friend sat down, and the twins were following his example. The Hydrogens in the lamp were cheerfully playing chase.
"The red sphere inside them indicates who they are. The gray spheres are basically nothing, usually just glue. It only makes the little ones heavier. But in the case of Hydrogens, the three of them have different names. The one with only one red sphere is called Protium, the ones with one red sphere and a gray is Deuterium, the glowing ones in the lamp are Tritium."
"The H(DT) sign at the train stop!", cried Conrad, then thought a bit. "Why isn't that P(DT)?"
"Because they are Hydrogen, Deuterium and Tritium!" Valerie riposted.
"Valerie is right. Protium is called in common Hydrogen. Although every one of them are Hydrogens. Comparing to the Protium, the Deuterium and the Tritium are more rare, so they are more expensive. That's why we will assort the harvested ones tomorrow."
"Why are they more expensive?"
"They are rare, that makes them expensive. But they are also used different tasks. For example Tritiums are used in paints, which glowing in the dark. Do you see them inside the lamp?"
"So the other ones are not glowing."
"Good! Very good! The other ones doesn't glow."
"Despite they are all Hydrogens?"
"Yes. They are all Hydrogens, but they have sometimes different nature, because their insides are different. Even their weight is different. These kind of little ones are called isotopes."
"Is this also an isotope?", asked Conrad, and lifted his little one a bit.
"No. It has two red spheres inside, not just one, like the Hydrogens. It is another kind of little one."
"So if the red sphere inside differs, it is not Hydrogen.", Conrad was thinking loud. K.O. nodded. "What is this one's name?"
"It is called Helium."
"Helium. So it is sure a different kind of little one. Why didn't it cry after born?", asked Valerie puzzled. "The Hydrogens are crying if they couldn't hold hand with each other!"
"Heliums, themselves have enough hands to hold. They have two hands. Do you see?" Valerie nodded, and stared at the little one, who was like hugging itself.
"But the Hydrogens have just one hands each."
"Hydrogens don't cry anymore, if they hold hands, Helium don't even cry, because it's two hands hold each other."
The kids were amazed, and they could barely get enough of the examination of the little ones. They were enthusiastically moving the button, and examining the little ones.
"K.O.! All Hydrogens have one red sphere, and have one hand, Helium has two red spheres and has two hands. Am I right?", asked Conrad excited.
"You are right. The number of red spheres inside define the number of hands of the atoms. They are the same in number."
"So if there is a little one with a hundred of red spheres, it has a hundred hands?", asked Valerie.
"Yes, but they are not too little, comparing to these cute little ones."
"It has to be bigger, because a hundred hands need a bigger surface." Valerie nodded seriously, and imagined a big sphere with hundred hands, as it walks like a spheroidal centipede.
"Well, they are different a bit from these little ones."
"How?"
"Hm. I think you'd better see them yourself! I won't take away from you the joy of discovery." said K.O., and winked to Valerie.
"Please tell us! Pretty please!", asked him the kids in unison. The old man shook his head.
"Come on! The ground starts brightening, so we need to switch to harvest mode! Conrad leads by one point, so Valerie has to work harder now!"
The next wave of the harvest ended by Valerie's win, and it was even at the last harvest. Neither Valerie, nor Conrad won, but they found more Helium, than before. K.O. put the quiet Heliums into a container under his bed. Since the last two harvest waves exhausted them and the field too, they went to sleep. K.O. wanted to relax a bit before the next day's work. He said sorting the little ones would be heavier work, than harvesting them. Valerie and Conrad both thought before drifting off to sleep, that they were actually happy despite the work, the strange sleeping place, and their difficult situation.
K.O. woke them up in darkness, and he got out two Tritium lamps. He had already attached a huge net to the side of the car and several small containers were lined up on the ground. The containers were numbered from 3 to 6. The twins looked at them carefully, while they were nibbling their chocolate bars for breakfast.
"It is the more interesting part!" K.O. called them to a small butterfly net, upside down. The net was attached to his palm device. "We will measure the Hydrogens."
The balloon on the car started to shrink, and the first pair of Hydrogens appeared at the end of a tube. K.O. grabbed the little ones, and put into the net. The Hydrogens tried to fly upward, but the net prevented them to escape. The display of the hand device showed number 2.
"They are common Hydrogens, so put them into the big net!" The man asked the kids. "Don't worry! This process is not harmful, just cause them a little inconvenience. So do it as quickly as you can."
K.O. was right. Although the little ones didn't liked the pushing out of the balloon and the measuring process, they became cheerful again, as soon as they were released to the net. This kind of work was a bit boring, until the display had shown number 5.
"We have found an expensive one!" K.O. pleased with the discovery. "Put it into the container with number 5."
"Why are they different in weight?" Valerie asked, since she was a bit bored.
"Do you remember the little spheres inside the Hydrogens?"
"The red one with a cross on it, and the gray one."
"They are together called nucleus. Basically it is the seed of the atoms. The red one is called proton, and the gray one is called neutron. They both have the weight of 1."
Valerie tried to count something in head, that's why she ended up running after the Hydrogens, K.O. had put into her arms.
"They are very lively, aren't they?" The old man laughed together with Conrad.
"Yes. But if the little ones' nucleus is weight 1, and two of them is weight 2, what is the weight of their hands?"
"Great question!" The old man praised the girl. "The hands are called electrons, and they are like a wrapping for the nucleus. Almost weightless. Like candy-floss." K.O. had let them examine the Hydrogens for a while.
"Candy-floss? It is very hard!" Conrad said disappointed.
"I told you they were not edible!" The man winked at them and they all burst out in laugh.
Later Conrad and Valerie started to competing on who could find more little things that didn't weight 2. This makes the monotone work a bit interesting. The work felt like it last for an eternity. There were a lot of Hydrogens, and there were few of those of exceptional weight. The green light was interesting at first, but towards the end they were no longer considered so special. It was dark, and some kind of fear caught the twins' hearts as they were selecting the little ones. The fear from the departure. It seemed the last work for their friend. When they would finish, they would go to find their grandpa without the help of old man, and it seemed to be very frightening. They enjoyed the work and the life with their friend, and were afraid of the unknown task of the future. So they slowed down, to extend the time they can still spend with him. K.O. noticed their behavior.
"When we finish with the sorting, a more interesting work will come!" , he told them, and the kids' mood lightened up immediately.
If there was still work, they did not have to go into the unknown so soon.
"What kind of work will that be?" Conrad asked him exciting.
"I don't tell you!" He pulled the boy's leg, and when Conrad get angry, he added quickly. "Yet."
The banter was a bit painful for the twins. Even if it was very friendly, it reminded them for the Class rep. Although even that girl was a memory, and she was obviously far away, the behavior of the girl still hurt them. They told this to their friend.
"In this case, I am sorry.", he said. "Don't you think, that girl wanted to be friends with you? Sometimes this kind of people just needs friends." The twins shook their heads.
"She was always malicious to everyone."
"She never wanted to make friends with us, just always educate everyone." Conrad said and shook his head again. "She is a very nasty girl."
"Then don't think about her! She is far away, and she couldn't educate you now, could she? Forget her, and the school! Enjoy this interesting world!"
Conrad and Valerie smiled at their friend, and K.O. smiled back. There was peace, and the twins forgot their school-problems.
"What will be that interesting work tomorrow?", asked Conrad again.
"You will see tomorrow, but at first, we have to finish selecting them. Maybe we will have time to watch into the irregular ones with the hand device! You would use on them, if you want!"
The kids became very happy for the promise of using K.O.'s hand device, so they speeded up the work. But it took a long time anyway. Hydrogens in, weighting them, and put into the net or to the right container. It seemed endless.
All work ends once, and the twins asked K.O. to continue with the interesting work after they had finished the selecting.
"Are you sure, you don't want to call it a day, and sleep?"
"Let's do, let's do!" Valerie was jumping from excitement to use the hand device.
"All right!", he agreed. "I have understood! Sleep could wait."