It's October, and Hogwarts has a long rainy season, and even the water level in the Black Lagoon has risen considerably.

The castle began to get wet, and the cold from outside continued to soak into the castle, and now the common rooms were lit with warm fires all day long.

I don't know what happened to Slytherin, but if I'm not mistaken, their lounge was just below the Black Lake, and it was already cold and damp. Maybe snakes like this kind of environment.

William never wondered why Slytherin wanted to live in such a hellish place, under the Black Lagoon, where people lived so deep?

If memory serves, the Slytherin common room was converted from a Hogwarts dungeon.

Although the Hufflepuff lounge is also underground, compared to Slytherin, which does not see sunlight all day long, the badgers' lounge is sunny all day long, and you can see the swaying grass and dandelions through the windows, which is a very warm and sunny place.

It's so close to the kitchen that you can eat whenever you're hungry.

However, it was very interesting to hear Draco say that their lounge had two huge glasses and could see the scene in the black lake, and if he was lucky, he could even see the giant octopus that lived in the lake, which was very interesting, William thought to himself.

He hadn't been there, and in fact, few students would enter the common rooms of other houses other than Harry.

The cold, damp air still caused many young wizards to catch a cold, thanks to the school doctor, Madam Pomfrey, who worked at St. Mungo's Hospital for Magical Injuries and Injuries in her youth, and was an excellent healer, dealing with countless conditions that were much more serious than colds.

With the help of her cold repellent, the students who had colds quickly recovered, but perhaps because the medicine was so effective, the ears of those who drank it would be steam white for the next few hours, like a train.

Another reason why the flu quickly subsided was the Medal of Cold, which William invented.

This year's sales have already begun, and after the experience, the progress can be said to be very smooth, whether it is an old student or a first-year freshman in this wet and cold day, there is a greater need for such a gadget that can keep warm from the cold.

Moreover, not only the Medal of Winter, but also the other mischievous products produced by William were also very popular among the students, and the students, especially the young wizards, naturally lacked sufficient resistance to these playful novelties.

Promoting prank products among students was a good move, William thought with some pride, although there was still a suspicion of plagiarizing the Weasley brothers' ideas.

Everyone is a reader, can the business of a scholar be called stealing?

What's more, compared to those big dung bombs or biting teacups that are almost tired of being played, these small toys made by William are more delicate and more playable.

This immediately attracted him to these energetic little wizards, who developed a variety of tricks without a teacher.

Gryffindor's twin brothers, in particular, used these things to trick Filch, and even smeared the flame anointing tube invented by William on Lady Loris, successfully creating a new magical creature, the Flame Cat.

When he saw Lady Loris, who was covered in flames, rushing into the Great Hall in a panic, Filch's heart must have collapsed.

The Weasley brothers really know how to play!

Eventually, Filch had all of William's inventions forbidden, and he had a new task every day, running around the school in the hope of catching any student who used or bought or sold William's pranks.

However, if a hoax product is not listed as a prohibited product, it only means that your product is not good, which is the exact words of the Weasley brothers.

And even if Filch repeatedly posted notices in the auditorium, prohibiting students from buying, selling, and using these hoax products, it could not resist the enthusiasm of the young wizards to buy them.

Things that were in the open have gone underground, making them even more expensive.

Thanks to Filch, he made Ravenclaw's money-making team and the leaders of the various colleges earn a lot more.

William's hunger marketing campaign was generally very successful, which made his custom accessories more and more expensive.

However, what the little snakes who are not bad for money want is this high price, so there are still many people who come to William through Draco for private customization.

It's still a student's money to make!

Inside the room, William waved his wand and turned the medal in front of him into a delicate silver serpent, and the two emerald emeralds turned into the eyes of a silver snake.

There was no way, Slytherin liked silver and green, which in their opinion were the colors of the nobility.

Regarding silver, William can understand, but green, with memories of his past life, has his own unique opinions on this special color.

In fact, William couldn't help but come up with this kind of marketing method, he now had too much research to do every day, and he had to have the dual training of Professor Flitwick and Professor McGonagall on the weekends, so he really couldn't squeeze in time to make alchemical products.

The plan to recruit new students did not go well

Now, William has taken over some custom-made products, and the rest is made through Pansy's alchemy workshop and mailed to Hogwarts.

At the thought of Professor Flitwick's training, William touched his ribs with some distress, he had just finished practicing with the professor yesterday, and now there was a faint ache there.

This year's professor is particularly crazy, probably because of the approaching dueling competition, he is more demanding of William.

William's own dueling level has also risen rapidly, and he has been able to compare with the professor back and forth for a while, which makes it difficult for Professor Flitwick to control his spell, and William gradually becomes a frequent visitor to the school hospital.

"I've already signed you up for this year's Wizarding Duel Tournament, but the first thing you need to do is pass the European qualifiers." Professor Flitwick said to William, who was slumped in his chair, with a gentle face.

Professor you definitely have schizophrenia, or split personality, William thought weakly, after a night of training, Rao is William's magic power far exceeds that of his peers, and he is also a little overdrawn at the moment.

"When are the qualifiers?" He asked weakly.

"Just during your sophomore break, a month before the game starts."

Wonderful Book House