Hearing Zhang Tie's cough, Donder raised his head from behind the counter. However, he didn't show any surprise, just revealed his teeth.
"Brat, you've come back here. Do you want me to invite you for a lunch?"
Zhang Tie revealed an innocent smile and honestly nodded.
Donder's face immediately looked as hard as the door plank of the grocery store.
"If so, I will go then. Previously I thought that if you invited me for a lunch, I'll give you something as a payment for your care for me in the past years..."
After saying that, Zhang Tie pretended to leave.
"Heh heh. You want to cheat me with this trick. Brat, don't forget that I taught it to you. I've already played and become tired of this trick dozens of years ago..."
Donder smirked behind the counter, seemingly having seen through Zhang Tie's lie.
Without saying anything else, Zhang Tie just pulled out of the original book
As was expected, when Zhang Tie pretended to leave again, Donder stopped him from behind the counter. "Wait a moment..."
Zhang Tie then turned back and stared at Donder with a smile. "How about that, you've changed your mind?"
"Wait a moment, I'll have somebody send the alcohol and dishes to our store. We'll talk here then. After two months, you look changed. You're taller now..."
Donder revealed a big smile.
Waving his head, Zhang Tie said, "Immortals Gathering Hotel!"
"What?" Although with that same smile on his face, Donder jumped up from like having been poked. He became infuriated and swore, "Bastard, do you know how much it would cost me to have a meal in Immortals Gathering Hotel? That is the most expensive Chinese hotel in Blackhot City. As it's chaotic now, the price of a meal there would be at least twice of one before!"
Zhang Tie didn't care one bit what Donder was talking about. Turning away, he went through the door.
"How about Delicacies House? That's also a nearby Chinese hotel. The dishes there are also good!"
Donder hurriedly rushed out from behind the counter.
Zhang Tie turned back and repeated for Donder's benefit, "Immortals Gathering Hotel!"
Donder gritted his teeth and glared at Zhang Tie, intending to find something in the latter's expression, but Zhang Tie looked calm, that's all. After struggling for quite a while, Donder finally compromised, "Brat, you win! If you dare to cheat me, I'll beat the sh*t out of you!"
Zhang Tie laughed loudly and pulled Donder away.
"Wait a moment, I've got a few pages not calculated yet!"
Zhang Tie walked over there. He took up the grocery's account book, and only after a simple glance, he started to jostle down numbers on the result column. Then he turned to another page, and with another glance, he wrote down a couple more numbers, after which he turned to the third page and scrawled down the rest of the results.
In less than ten seconds, he had calculated all the three pages which would have taken Donder ten minutes to finish it.
Putting down the pencil, Zhang Tie patted his hands.
"Bad*ss, what are you scrawling on my account book..."
Dumbfounded for a while by what Zhang Tie was doing, Donder rushed over there, glaring at Zhang Tie with the solemnity of a funeral ceremony. After tthat, he hurriedly took up the abacus and started to calculate the numbers.
In less than three minutes, Donder's expression had changed. On the first page, none of the numbers written down by Zhang Tie were wrong.
'How could he be that fast? Even with mental arithmetic, one could not know all the results with merely one glance.'
Donder had no idea that Zhang Tie's mental arithmetic by abacus had reached a level that could not even be imagined by the boy himself after surging three more times. With merely one glance over the numbers, the answers appeared in his mind, which was one hundred times sharper than the common mental arithmetic in modern times.
"Do you believe me now?" Zhang Tie waited to the side until Donder twisted his face and looked at him with a doubtful expression. "Don't worry about the other calculations. Don't waste anymore time!"
"When did you learn such sharp mental arithmetic?"
"That's not mental arithmetic, but a side effect of Mental Arithmetic by Abacus..."
"Side effect?" Donder asked with disbelief.
"Side effect!" Zhang Tie confirmed, nodding his head.
Donder finally revealed a big smile on his face. "Well, Immortals Gathering Hotel!"
Immortals Gathering Hotel was the most advanced Chinese hotel in Blackhot City. Before everything, eating here for Zhang Tie was almost as difficult as climbing into the sky. The lowest per capita consumption here was never less than one gold coin.
Before the entrance to the Immortals Gathering Hotel were a pair of stony lions with Chinese characters. It was heard that the architectural style of the entire hotel was Chinese classical style: gray tiles, cornices, verdant trees, and red windows. The architectural style was unique in Blackhot City.
On the Horizontal Board were three Chinese characters 'Immortals Gathering Hotel' and two huge vertical columns with two Chinese couplets on them:
——Under a half burned oil lamp, one holds half a cup of alcohol and enjoys a fraction of happiness in the human world, though half-drunk.
——With immortal pals, friends, dishes, and alcohol, one invites fairy maidens to share the drink in the immortal house.
These couplets surrounded the three Capitalized Chinese characters in the middle: Immortals Gathering Hotel!
There was only one hotel like this in the whole of Blackhot City.
After entering through the gate of the Immortals Gathering Hotel, they saw a rock garden with rivulets flowing down and across. Two rows of blondes with plump breasts greeted them in skintight cheongsam with openings reaching their thigh.
The moment Donder and Zhang Tie entered, the two rows of blondes bowed together towards them, saying in an orthodox Chinese 'Welcome', which really shocked Zhang Tie.
Ever since he was born, it was his first time seeing so many foreign girls speak Chinese in unison.
The pale yet elegant skintight cheongsom, black high-heel shoes, snow white legs, and the plump breasts that were exposed through their 'V-shaped' collar when the blondes lowered their heads almost made Zhang Tie's head spin.
Donder walking in front did not pay attention to the bowing women since he was used to it. However, Zhang Tie abruptly felt his legs go soft and almost fell down.
"What's wrong?" Donder glanced at Zhang Tie with uncertainty. "Weird, what's wrong with you today?"
At this time, cold sweat had already covered Zhang Tie's forehead. Just now, when he caught sight of the lined pairs of plump breasts, his untamed thing reacted, causing a sharp pain between his legs. Just having been circumcised, that spirited thing pained Zhang Tie so much that he almost went down and squatted on the ground.
"It's okay, it's okay!" Zhang Tie said with a trace of fear and wiped off the cold sweat from his forehead.
After, he slowly picked himself up.
'I forgot about this!'
Zhang Tie swore inside. His original plan was to let Donder bleed by spending a lot to invite him to the Immortals Gathering Hotel, the most expensive hotel in Blackhot City, which Zhang Tie had no chance to have ever visited before. Unexpectedly, he was almost killed by the cheongsam blondes outside the hotel.
With narrowed eyes, Donder glanced at Zhang Tie, then the beautiful and sexy greeting girls. Immediately, he revealed a shadow of obscene smile at the corner of his mouth.
Straightening, Zhang Tie didn't dare to look around anymore, just followed Donder inside.
"I want a quiet chartered room. Two more waiters to help lift my younger fellow who has something wrong with his body!" Donder ordered. For some reason, he emphasized the words 'younger fellow'.
With a blow of fragrant wind, two blondes arrived and started to lift Zhang Tie's arms enthusiastically.
Before refusing them, the moment he smelt the fragrance, Zhang Tie was greatly pained again and squatted down. It was his turn to glare at Donder this time.
"You're doing this on purpose, aren't you?"
"What are you talking about? What am I doing on purpose? "Donder rebutted with an innocent expression, shrugging his shoulders.
"You must have known about my thing. You dare to say that you don't know what I'm talking about? You're just playing with me!"
The blondes standing aside stared at the two people quarreling at the entrance of the Immortals Gathering Hotel with eyes wide-open.
"Do you mean you've had circumcision today?" Donder pretended to think about it for a quite while before he shouted it out. It was so loud that even people from 30 m away could hear it.
After his scream, many blondes standing nearby burst out laughing when they caught sight of Zhang Tie's awkward look squatting down on the ground. Afterwards, they realized that it was impolite to do that, so they forcefully stood it. However, they started to glance at that place under his abdomen.
'Revenge, this was definitely revenge. Donder the bastard loudly revealed my secret in public to shame me, forcing me to change to another place. I'll make him pay for it!'
Zhang Tie gritted his teeth and picked himself up from the ground without peering at the beauties nearby anymore, instead, he shouted out loudly, "Where's your most expensive chartered room? Take me in, I'm hungry!"
This time, it was Donder's turn to twist his face.
Several minutes later, in a luxurious chartered room of Immortals Gathering Hotel, Zhang Tie started to order dishes. Each dish he ordered would make Donder's fat face painfully quiver. When he ordered the eighth dish, Donder started to gaze at him with fury.
"Bad *ss, can you even eat so many dishes?" he painfully screamed out.
Zhang Tie didn't ignore him but asked a waiter standing next to him, "Can I take them away if I can't eat them all?"
"No. The food and dishes in Immortals Gathering Hotel can only be taken away in your stomach," the waiter politely answered.
"Alright. I'll then just taste some more..."
Zhang Tie laughed loudly and ordered eight more dishes before stopping with satisfaction.
By the time he did so, Donder was already gasping with red eyes on the other side of the table.
The older man asked, "Have you finished then?"
"Yes, I have!" Zhang Tie gave him a big smile.
"Well, it's my turn now!" After saying that, Donder turned to the waiter. "Please send me two blondes. I want the coquettish ones with little clothing."
After saying that, Donder glared at Zhang Tie who was also ferociously glowering at him.
"I've forgotten, I want lark-dragoon soup!"
Zhang Tie gritted his teeth and added one more dish.
"Two blondes are too few, I want two more: one on our right side, and the other on our left side. That would be more interesting!"
Donder gnashed his teeth.
"We have to drink alcohol. I want one bottle of Cloud-Immortal Alcohol!"
Zhang Tie clenched his teeth.
"We have to have dancers for alcohol. Go fetch me one voluptuous dancer here, the sexier, the better!"
Donder added one more dish for Zhang Tie.
The two then furiously glared at each other while panting like fighting roosters, killing intent filling their eyes, the reason for which could only be understood by them alone.
Feeling not right in the room, the waiter silently slid out...
Several minutes later, along with dozens of yummy dishes came a group of charming and plump blondes, accompanied by two qin  and drum musicians.
This meal was very painful for both Zhang Tie and Donder. Donder's heart bled for the high costs while Zhang Tie felt real pain in his wounded flesh.
It took them over an hour to finish this meal; they both looked pretty rigid by its end. Donder's fat face twitched every now and then while Zhang Tie's sweat kept rolling down his forehead. This meal almost made the two of them faint.
In the end, looking at the awkward expression of the opponent, one of them forced a smile and then the two of them burst out laughing at the same time.
Donder waved his hand to let all the dancers and musicians move away.
"Brat, you win. I've not been madder at anyone in the past dozens of years. I feel that many years younger being around you. How about that? Do you still hurt now?" Donder asked.
"Thankfully, I found that drinking alcohol can relieve pain and transfer one's attention! Later on, if anyone dares to say that you're mean, I'll spit all over his face. This meal will cost you at least 5-6 gold coins."
Zhang Tie also relaxed and leaned against the chair. The past hour was really a torture for him. It was no different from suffering a criminal penalty and more torturous than staying in the dark cell.
"5-6 gold coins? Rustic. It's not enough to even pay the women. Plus the dishes and two gold coins' chartering fee, it will at least cost me 15 gold coins!" Donder widely opened his eyes as he shouted loudly.
Zhang Tie sighed inside as 15 gold coins were even higher than his dad's one-year salary. When he was driven angry just now, he hadn't realized that, but after recovering his composure, he started to realize that it was a really great harm to Donder. It would take his grocery store at least two months to make 15 gold coins at a normal speed.
So after hearing that, Zhang Tie felt embarrassed and scratched his head. After thinking for a while, he directly pulled out of the book
Donder solemnly took it and seriously skimmed it from beginning to end. As a person who excelled at making calculations on a real abacus, of course, he understood the basic principles of Mental Arithmetic by Abacus.
"Hmm, this is a mental arithmetic based on virtual abacus. It's fashionable and one level superior to directly calculating on a real abacus. You didn't cheat me, brat. This meal is worthwhile!"
After reading the entire book, Donder satisfactorily nodded before putting it into his coat.
Hearing Donder's reply, Zhang Tie smiled, shaking his head.
Donder was stunned.
"What? Am I not right?"
Zhang Tie didn't speak but pointed at his own mouth, shaping his mouth in silent words 'spiritual energy'.
Since Donder had taught him the lip reading skill, which was a communicative skill used by many pioneers, Zhang Tie was sure that the older men could clearly understand what he was saying.
They were in a chartered room in a hotel, so Zhang Tie had to be careful. Now even if someone was eavesdropping, he could not hear anything about the secret.
As expected, seeing Zhang Tie's mouth shapes, Donder was dumbfounded. His eyes popped out with disbelief.
So Zhang Tie continued by moving his lips, "By practicing mental arithmetic by abacus, you can improve your spiritual energy. I've tried it. This might be the easiest way for everybody to grasp the secret to improve one's spiritual energy..."
Shocked, Donder picked himself up from the ground where he had crashed next to the table. He opened his mouth, seemingly wanting to shout out from amazement, but he knew better and covered his mouth with a hand.
In any place, any method that could be used to raise one's spiritual energy would be very important.
He then just gazed at Zhang Tie without even winking.
Zhang Tie nodded seriously.
After departing from Donder and returning home, it was almost dark. On the way back home, Zhang Tie took a look at the grains store. He found that the price of 25 kg of rice had truly risen to 10 silver coins, which was twice as high as three months ago. Such a high price would definitely lay a heavy burden on many commoners. Although it was not very severe, not to the point of the sky collapsing anyway, such a high rise had already greatly influenced many families' daily lives. They started to live in a more frugal way.
In the afternoon, Zhang Tie had also went to the Iron-Thorns Fighting Club. What made him disappointed was that the gate of the fighting club was tightly closed this time. It seemed to have been suspended for a few days.
In the past month, many things in Blackhot City had changed.
Avenue Bright, the most prosperous place in Blackhot City seemed to have lost its original brilliance. Almost one third of the stores had been closed. As to the rest, although they opened, they weren't as sought out as before.
In the entire Avenue Bright, many roadside stores and houses were marked with transfer and for sale.
The prices of fixed assets in Blackhot City like real estates started to sharply decline; many people were dumping them. In contrast, the prices of daily necessities like food, weapons, and medicine materials had started to surge. Even prices of resources like coal, iron, and steel had started to slowly raise. This was the current condition of Blackhot City that Zhang Tie saw after circling around for half a day. It did not look like a promising sign.
When Zhang Tie slowly returned home, he found that the door of his house was encircled by a great many people, making the outside of his house noisy. It seemed that someone was stirring up trouble there...
'The cheongsam is a body-hugging one-piece Chinese dress for women, also known as qipao.
 'Qin' is a classical Chinese seven-stringed plucked musical instrument in someways similar to a zither.