It's been a few days since the party, and of course what Seamus said casually has also gained green sparks, but he doesn't care, theoretical knowledge is forcibly improved, and it can't compare to those who have studied seriously for several years, which is normal.

As a pure otaku, he basically stays in the dormitory when he has nothing to do, either reading a book or going to the suitcase to study the magic array, and the other three roommates basically don't stay in the dormitory during the day. In the wizarding world, especially at Hogwarts, even if he had a large sum of gold gallons on him, it was of little use, and there was not even a commissary in the school.

Except for going to Hogsmeade, the only way to buy things was through the Owl Express, and he had nowhere to go if he wanted to spend money, so Seamus used the warehouse to store countless books, and his whole day was to stay in the dormitory.

"Come on, we've made it. The twins suddenly rushed in, with an excited expression on their faces, and pulled him out.

"What are you going to do?" said Seamus, who was staggering and could only follow them.

As they ran out, the twins explained to him, "We've made something that emits smoke, come and have a look." ”

After a wild run, Seamus followed them to an empty underground classroom, at the end of the corridor on the negative floor, the twins looked left and right, found that no one was following, closed the door of the classroom, and led him to a cabinet in the classroom, "Come in, this time take you to a good place." ”

In this way, Seamus was forced into the cabinet by them, and then George and Fred followed, and the three of them seemed a little crowded in the cabinet, but fortunately, they were all still children, and they were not big, and they could barely squeeze in, Fred closed the door of the cabinet, and it fell into darkness, but soon Fred dispelled the darkness.

"What are you doing here, hurry up and get in. Fred pushed George and told him to hurry up, and George said unhurriedly, "What's the hurry, and no one is coming." ”

Then George banged on the side panel of the cabinet, and there was one place that made a different sound from the others, as if the back was empty, but the back of this side panel should be close to the wall, and George said happily, "This is it." ”

He used his wand to cut open the plank, and there was a rope in it, and George pulled it out, and the side panels of the cabinet moved with it, revealing a dark passage and a narrow, damp staircase that snaked down.

When he came to this classroom, the map had already explored the secret passage here, and he really rarely came to the underground classroom, except for the Potions class, he wouldn't even go this way at all, not to mention the empty classroom at the end of the corridor, which had never been discovered before.

This underground classroom is so remote that even the house elves forget to clean it, whether it is a desk or a chair, there is a thick layer of dust, and there are ceiling slag scattered on the ground, it is estimated that no one has cleaned it for more than ten years, only the door to the middle of the cabinet, which was stepped on by them.

As they descended the stairs, the air gradually became more and more humid, and the map gave Seamus the most accurate answer, and they went down one hundred and twenty-two meters, which was already at the bottom of the Black Lake. After walking up the stairs, they came to a wide passageway, made of marble, which was very damp and cold, and the walls were covered with glowing moss, illuminating the dark place.

Ten meters above their heads was the bottom of the Black Lake, but the marble blocked the water well, and there was no dripping water, but the air was very humid. The walls are damp all year round, and the air smells of rotting wood.

"This is another secret passage we've found, leading to the island in the middle of the Black Lake, which is a wide place where no one will notice. Fred was beaming with pride, and the two of them looked extremely comfortable and relaxed after entering the corridor.

"This is our secret base, and if you hadn't helped us so much, we wouldn't have brought you here. George put his hands behind his head and walked forward as if he were home.

"yes, it won't be noticed. Seamus looked at the feedback from the map, there were still a large number of mermaids living at the bottom of the Black Lake, although they were not very beautiful, but they were undoubtedly one of the few magical beasts with intelligence. Now above them is a mermaid village, with hundreds of merfolk cruising around with forks.

The mermaid can survive in Hogwarts and avoid being disturbed by other wizards, and must have reached an agreement with Hogwarts, and Dumbledore's most famous foreign language is the mermaid language, so others may not know the situation on the island in the middle of the lake, but Dumbledore must know the twins' movements.

The passage was less than three miles long, and much wider than the one behind the one-eyed witch, and they could walk more comfortably, and in less than half an hour they were on the other side of the passage, which was also a narrow staircase, equally dark and slippery.

They came up the stairs to the surface, and the exit was inside a large tree, which was as thick as three people hugging each other, but not very tall. Unlike the beech trees in the Forbidden Forest, which were hundreds of feet long, this tree was less than 20 feet, but it was very thick, and the trunk was hollowed out, enough for a person to pass through easily.

They came out of the trunk and put the bark back in its place, and the trunk was back to its original state, and nothing unusual was seen from the outside. It's three miles from the castle, and whatever happens on this side is hard for anyone on the other side of the lake to spot.

"Look, this is our secret base, only the two of us know about it, and now it's going to add you again, don't tell this secret. George took a deep breath, felt the fresh air, and turned back to him.

"No problem, I'm sure I won't tell anyone. Seamus patted his chest and assured him that there was still a mermaid lying on the shore anyway, and he said that it would make no difference if he didn't say it, "Are we here to test that smoke-emitting thing, why don't you use this as a laboratory?"

"Of course, because of the abundance of materials in the storage room, we didn't have much money to buy any raw materials at that time, but we could consider building a house here in the future. George was fiddling with something on the ground without looking back.

"Look at the smoke that won't be dispelled by the spell according to your requirements, the visibility is extremely low, and it's best to be able to move around. Fred explained next to him, and there was a bottle on the ground with something black in it, "I saw it in a book, and it took a long time to make it, and the bottle contained soul exorcism ointment, and once lit, it could emit a large amount of black smoke, and it could not be dispelled by a spell, and even the spell had no effect on it at all, and this was the only way to dispel it." ”

Fred took out another bottle with a white liquid, "This is the method of lifting the soul exorcism ointment, it is called soul revival water, as long as you pour the soul revival water into the black smoke, it will absorb all the black smoke." ”

"You're amazing, but why they're called that doesn't sound like they have anything to do with souls. Seamus took the bottle from Fred's hand and found that the water contained was similar to milk, it was milky white and could stick to the glass bottle.

"That's because the original formula of the exorcism paste has coca leaves in it, which can make people who smell it feel dizzy and feel the soul out of the body, so it is called soul exorcism ointment, and we removed the coca leaves for the safety of the experiment, so the black smoke emitted is not dangerous to people, at most it is just a little choking. George fiddled with the things on the ground, and the mouth of the bottle was opened, and only a thin layer of exorcism cream was placed inside.

"Keep your eyes open and look at it. With a flick of Fred's wand, a little spark flew out of the tip of the wand and landed precisely inside the bottle, and the black exorcism ointment ignited a thin flame, and then Seamus couldn't see anything.

His last impression was that a large cloud of black smoke was like a flood opening the floodgates, gushing out from the mouth of the bottle, and suddenly fell into darkness, and the smell of black smoke was a little pungent, which made him want to cough. Through the observation of the map, he found that the black smoke only surrounded the bottle, and now the breeze on the lake did not affect it at all, and it was firmly gathered around the bottle.

"Well, it's not bad, it's not too much wind and rain, and it doesn't have any effect on these black smokes. George's voice came from the side, and Seamus couldn't see him even when he was close, but fortunately the map was not affected by the black smoke.

Seamus slowly put his hand in front of his eyes and measured the approximate visibility, which was only about ten inches, which was the distance of a wand. There was no more black smoke from the bottle, presumably the exorcism ointment had burned out, he uncorked the bottle on his hand, and the black smoke floating in the air poured in, and the light came to them again.

Plug the mouth of the bottle, the milky white soul water inside has been reduced a little, and the bottle that was just full of soul water is missing, and it should have disappeared together after neutralizing the black smoke.

"A full bottle of Exorcism can burn for about five minutes, and the black smoke emitted can envelop half of the Quidditch pitch. The two of them stood in front of Seamus, George handed over a full bottle of exorcism ointment, and said with a smile on his face: "It's that this thing is more expensive to configure, and it will cost you a lot more if you need it." ”

"No problem, this thing just fits my requirements perfectly. Seamus took the bottle from his hand, put it away with the Soul Water, and then took out another bag of gold Galleons and handed it to George, "I want to trouble you to make a little more, I want to keep it for later." ”

"That's easy to say. George took the gold galleons, put them in his telescopic pocket, and agreed, "But what are you doing this?" ”

"Of course, it's used to escape for your life, and if you release a large cloud of black smoke, others won't be able to see you, and then you can slip away. Seamus gave them a ninja look.