I've already become a Hogwarts professor, and the system only just appeared.

Tonks thought for a moment: "Then let's sit in the front. I've never ridden in a Muggle's car before."

After getting into the car, Tonks looked around like a curious child, exclaiming, "It's unbelievable that Muggles can actually build cars that can run on their own."

As Su Yu started the car, he said, "Don't underestimate Muggles. The most powerful weapon that Muggles can create right now can destroy the entire city of London in a second, leaving not a blade of grass standing."

Tonks stared at Su Yu for a long time, trying to figure out if he was joking, before finally saying, "How is that possible!"

Su Yu knew that this kind of thing couldn't be explained to a wizard who had always lived in the magic circle, so he changed the subject. The two chatted casually and drove to Thames Street, where Su Yu's house was located.

It was a low-rise, red-brick building in the British style. More than a decade later, the Muggle Expulsion Charm and Confusion Charm were still effective, making it impossible for the surrounding Muggles to find it.

Upon opening the door, the room was very spacious, with five floors including the basement. However, it was in a mess, with scorched marks left by the curse visible everywhere on the floor, ceiling, and walls.

"My God, Sue! How many Death Eaters did you fight before you left here?" Tonks exclaimed in surprise as he looked at the devastation.

"Hehe, not many, just 10!" Su Yu waved his hand, looking nonchalant.

"Are you the only one?" Tonks' eyes already sparkled with admiration.

"Of course, it is definitely not a good choice to rashly enter the room of an alchemy master. Although I am alone, I have quite a few trinkets in my room."

"If I remember correctly, two Death Eaters died and four were injured in that battle," Su Yu reported his battle record.

"So how did you finally escape?" Tonks asked again.

Su Yu said, "The Portkey. From the first day I started fighting Voldemort, I knew this day would come, so I prepared the Portkey in advance. It teleported me directly to France, and then I went to America."

The two chatted as they made their way to the basement. Su Yu rummaged through the ruins and quickly found a small black bead. He was delighted and put the bead away.

As he told Chen Ying, he had a reason to come back: revenge. He would repay the Death Eaters tenfold for how they had treated him.

Over the past decade or so, he has simulated this process in his mind more than once, but unfortunately, his own magical level is too low. If he cannot prepare in advance, the alchemist will find it difficult to exert his combat power.

Things are different now. Having experienced the rapid increase in magic power, his mind has become more active, and this bead is an important aid on his path of revenge.

“Alright, our next task is to restore this place to its original state. In return, you can get the right to live in one room, so you won’t have to look for a place to live nearby,” Su Yu said to Tonks.

“That’s a huge project!” Tonks said, frowning.

For the next three days, Tonks and Su Yu kept using the "Restore to Original State" function in the house, trying to restore it to its original appearance.

If it were just physical damage, it would be relatively easy to repair, but most of the damage here was caused by magic, and much of it was even caused by evil black magic.

Even after more than a decade, the evil aura emanating from it remained difficult to dispel. It took Su Yu several attempts to create black magic absorbers to finally resolve the problem.

With his magic power increasing by two levels, Su Yu could clearly feel that he was becoming more adept at alchemy. Perhaps it wouldn't be long before he could break through to Alchemy Level 9 on his own.

For the next month, Su Yu basically stayed in the repaired basement and continued his research.

His main research project is still the magic phone. This thing has many drawbacks. First of all, it is very expensive to manufacture. The raw materials alone cost 10 Galleons.

Secondly, the process is complex. A small mobile phone needs to include Floo teleportation runes, information display runes, display runes, input runes, etc., which can only be made by hand and is very time-consuming.

Finally, it has limited functionality and lacks server support. The current Magic Phone is essentially a simplified version of WeChat, only capable of adding friends and chatting.

After a month of research, Su Yu made no breakthroughs, but he did manage to manufacture a few more magic phones.

At the end of August, Tonks found Su Yu and said, "Su, the Ministry of Magic has issued a new order to cancel your protection. I think I should leave."

"Oh, why?" Su Yu asked curiously. He understood, of course, that this so-called protection was just another way of saying surveillance.

As a cooperating alchemist with the Magical Congress of the United States, it was normal for him to be regarded as a suspicious foreign wizard by the British Ministry of Magic after suddenly arriving in Britain. However, the sudden cancellation of protection left him somewhat bewildered.

Tonks shrugged and said, "Perhaps Headmaster Dumbledore made assurances to the Ministry of Magic that they would be responsible for your safety while you are at Hogwarts."

It turns out that Old Deng was the guarantor, which makes sense. Su Yu said, "Alright, I'm going to school in a couple of days anyway, so I'll give you two things before I leave."

After a month of getting to know each other, Tonks and Su Yu have become true friends. Su Yu really likes this girl's personality: kind, straightforward, honest, optimistic, and sometimes a little silly, which is kind of cute.

"What is it?" Tonks was very excited. After spending a month together, she realized just how amazing Su Yu's alchemy skills were.

"The first item is this; you've probably been eyeing it for a long time!" As he spoke, Su Yu pulled out a Colt Python revolver.

Tonks nodded immediately, like a chicken pecking at rice. She remembered clearly how Su Yu had used this thing to take her down in no time.

"Is this the alchemical tool that defeated me back then? What's it called?" Tonks asked excitedly.

Su Yu rubbed his nose and said, "It's called the Magic Pistol. It's from the same series as the one I used back then, but it's slightly different."

"Enter magic power and pull the trigger to activate the spell. There are six slots: Exterminate, Swift Imprisonment, Blazing Flames, Tongue Lock Throat, Stun and Thunder Explosion."

"You'll get used to it after a few tries, but my advice is to avoid using this unless absolutely necessary. It does more harm than good to your spellcasting level."

"Okay, okay!" Tonks happily took the magic pistol and gently stroked it, like a child who had received a new toy.

Chapter 9 The Boy Who Survived a Great Calamity

The magic pistol is Su Yu's current flagship product. With it, Su Yu invested his technology and partnered with the Stuart family to establish a magic weapon factory.

Although his shareholding was not high, the annual dividends were enough to make him very wealthy. Most importantly, it gave him a foothold in the United States.

While Su Yu is said to be an important partner of the Magic Congress of the United States, the actual partner is this factory. Currently, almost every combatant of the Magic Congress is equipped with a magic pistol.

The advantages of the magic pistol are obvious: it can be cast quickly, silently, and without a staff, often catching opponents off guard. Tonks knows this all too well.

The standard magic pistol also has obvious drawbacks: its spell power is relatively weak, and it cannot cast spells like the Levitation spell, which requires a continuous output of magic power.

Prolonged use can also cause wizards to become dependent on it, thereby reducing their own spell power.

The second thing to give to Tonks was naturally the magic phone. Su Yu demonstrated how to use it to her and added her as a friend.

It was clear that Tonks preferred the magic phone to the magic pistol. For a while afterward, even when the two were sitting face to face, Tonks would use the magic phone to chat with Su Yu.

September 1st has arrived. Tonks has been gone for three days. Su Yu has packed his bags and, with Coal Ball in tow, arrived at King's Cross Station, ready to board the Hogwarts Express and head to Hogwarts.

As soon as Su Yu arrived at the station, he saw a large family walking towards him from afar. Most of them had red hair, so who else could they be but the Weasleys?

Arthur Weasley, who was leading the group, was the first to see Su Yu. He paused for a moment, then quickly went to Su Yu's side, patted Su Yu's arms hard, and said:

"Su, oh my god! It really is you! I knew you were still alive, I'm so glad to see you again!"

During the Second Wizarding War, Arthur was the logistics minister of the Order of the Phoenix. Although Su Yu did not join the Order of the Phoenix, he provided them with many alchemical tools, and Arthur was the liaison between the two sides.

Su Yu patted Arthur on the shoulder and laughed, "Arthur, you haven't changed much over the years. Introduce yourself to me."

Arthur quickly turned around, beckoned everyone over, and said, "This is my wife, Molly, whom I've told you about before; Molly, this is Su Yu, the former genius alchemist."

Molly had obviously heard of Su Yu before. She stepped forward and hugged him, saying, "Su, it's a pleasure to meet you. Arthur used to praise you to me often, saying that you are the most talented alchemist of the younger generation."

Arthur then introduced Su Yu: "This is my third son, Percy, who is in fifth grade this year. These are George and Fred, who are in third grade this year. This is Ron, a freshman this year. And this is Ginny, who will start school next year."

After greeting the children one by one, Arthur continued, "By the way, Sue, why are you here?"

Su Yu said, "Of course I'll take the Hogwarts Express. In fact, I'm already a professor at Hogwarts, and starting this year, I'll be in charge of the Muggle Studies class."

"Muggle Studies? No, Su, with your level, you should be teaching alchemy," Arthur said, defending Su Yu.

"Haha, Arthur, I remember you used to be very interested in Muggle items, how come you look down on Muggle Studies now?" Su Yu teased with a smile.

Arthur waved his hand: "No, no, no, I absolutely did not look down on Muggle Studies, it's just... never mind, it doesn't matter what we teach, as long as you're back."

As they chatted, they walked toward Platform 9¾. Along the way, Arthur told the children about the magical items that Su Yu had invented, so that his children could ask Su Yu for help with any questions they had at school.

Percy was somewhat disillusioned with this, believing that the position of Muggle Studies professor at Hogwarts was entirely dispensable and that such a teacher would not be of much help to him.

But George and Fred were different. Both of them had considerable talent in alchemy and were keen on creating prank alchemical gadgets.

Upon hearing that Su Yu was incredibly skilled in alchemy, the twins immediately decided to take a Muggle Studies course this year.

As for Ron, he was somewhat introverted, timid, and didn't dare to speak much.

As the group arrived at platform 9, Su Yu spotted a boy standing between platforms 9 and 10 from afar.

He had black hair, looked thin, wore glasses, and was dragging luggage with an owl cage on top.

If I'm not mistaken, this person should be the legendary Harry Potter. At this moment, Harry was a little confused and kept looking around, hoping that someone could help him.

Su Yu didn't rush over. After Percy passed through the platform wall and disappeared, Harry clearly noticed that this group of people was different from others.

Approaching Molly, he said, "Madam, are you heading to Platform 9¾? I'm also a new student at Hogwarts this year, but I can't find Platform 9¾."

Molly was clearly a kind person. She patted Harry's head and said, "Don't worry, kid. This is my son Ron. He's also a freshman this year. In a bit, you push your luggage and head over that wall."

“Remember, you must believe that you can get there. Ron will be behind you, understand?”

Just then, a gust of wind blew by, lifting Harry's hair and revealing the lightning bolt-shaped scar on his forehead.

"Oh my god, you are... Harry Potter?" Molly took a step back, covered her mouth, and exclaimed.

At this moment, everyone else looked over, staring at Harry. Fred and George, being the most lively, leaned over and asked, "Really? You're really Harry Potter?"

Harry seemed a little flustered and awkwardly said, "It's...it's me. Do you all know me?"

“Oh, child, of course I know you. I held you when you were little. I should have recognized you long ago. You look just like your father, except for your eyes, which resemble your mother’s,” Molly exclaimed.

“Can you tell me about them? My parents?” Harry asked, pleasantly surprised.

“Sorry, honey, this isn’t the time for this. We need to get into the station,” Molly said, seemingly remembering something, changing the subject.

"Molly, why don't you let me take these two children inside?" Su Yu suddenly said from the side.

It wasn't that Su Yu wanted to get involved with the savior Harry; just as Harry was admitting his identity, Su Yu received his second main quest.

Mission Name: The Boy Who Survived

Mission objective: You encounter the legendary boy who miraculously survived a near-death experience at the train station. He seems to be hiding some unknown secret, which immediately attracts your attention. Try to learn about his past. Reward: 1 General Skill Point.

Su Yu wanted to say that he didn't attract her and that she knew all his secrets, but the system obviously didn't think so.

Su Yu thought that, according to the system's logic, the mission would probably be considered complete only if he heard about Harry Potter's past from someone else.

To verify his hypothesis, Su Yu decided to travel in the same carriage as Harry and Ron on this trip, and also try to make more friends to see if he could trigger the second reward of "Finding Friends".

Chapter 10 The Hogwarts Express

"Oh, that's wonderful!" Molly clasped her hands together and thanked Su Yu.

Su Yu came up behind Ron and Harry, put his hands on the two children's shoulders, and said to Harry, "I am also a professor at Hogwarts. I will count to three, and you will push the cart forward. Do not hesitate or doubt. Do you understand?"

Harry and Ron both nodded: "Yes, Professor."

"One, two, three!" Su Yu counted to three, then pushed with both hands, sending the two children crashing into the wall in front of them.

When the stroller made contact with the wall, both children closed their eyes in fright, and then they felt as if they had bumped into a flexible membrane.