Chinese students at Hogwarts.

The lake water is freezing cold, and Zhang Xiao has not used the Head Soaking Curse yet, because through the Head Soaking Curse, his observation of the outside world is actually somewhat distorted.

He felt the rapid loss of heat and secretly clicked his tongue. At this moment, he heard several other dull sounds.

It was Harry and the others who also came down. Zhang Xiao made a few simple gestures to them to let them get used to it first.

The water temperature under the ice is basically fixed at 4 degrees Celsius, which is very low. The situation that froze Jack to death when the Titanic sank is almost the same as it is now.

Sure enough, there was a problem with this adaptation. Zhang Xiao found that Xiao Ma's body was twitching slightly, and his hands and feet were as stiff as two logs.

As a last resort, they immediately returned to the lake and got into the warm tent with a fire pit. Zhang Xiao waved his wand to dry Malfoy's clothes.

Hermione handed over a blanket and a cup of hot cocoa. The little witch's face was pale and not very pretty.

Malfoy thanked him shakily and took a big gulp of hot cocoa, feeling a little better.

"What happened?" Harry and Ron were confused. Although they felt uncomfortable when they first entered the water, they didn't have such a big reaction.

I had just entered the water, but I saw Zhang Xiao constantly gesturing to float up.

Cedric dried the clothes of the other little wizards and took out a few stalls, but he understood Malfoy quite a bit.

"Draco has no experience diving in this kind of water before, so he is not used to it."

Malfoy nodded and said with some fear:

"Well, after I went down, I just felt my heartbeat was pounding, there was a constant ringing in my ears, my hands and feet were numb, I couldn't breathe, and I couldn't move anything."

"Cold shock -" Zhang Xiao said with certainty. This was knowledge he had learned when he was diving in his previous life, but like most people, he only had a taste of what he did in his previous life and just tried it.

Seeing that the little wizards were still a little confused, Zhang Xiao could only explain further:

“Prolonged immersion or just entering cold water may cause cold shock, which may be manifested by the inability to control breathing or hyperventilation.

Dizziness, tinnitus, numbness of hands and feet, and loss of consciousness occur.”

The little wizards were frightened when they heard this. These were the fruits of research by Muggles. Zhang Xiao originally thought that wizards' instinct to distort damage would allow them to avoid this risk.

But it seems that they will not instinctively try to avoid the impact of this environment as they would directly face the harm.

Neville listened silently. He was the person in the best physical condition except Zhang Xiao. Taoism paid more attention to physical exercise than wizards, and generally had an advantage in this situation.

But he couldn't help but said:

"So even if this doesn't happen at the beginning, it will still happen after a long soaking time?"

Zhang Xiao nodded.

"So we have to think of something and I don't think the second round will be over in an hour or any time."

Hermione got to the point.

In fact, there are still many problems, such as diving sickness, which Zhang Xiao did not mention. Wizards have good recovery methods in this area, and they are only afraid of a few special things.

The atmosphere in the tent became silent. No one expected that the problem before them would be so difficult.

Just entering the water at the first level stumped them, and they knew from the previous discussion that the ruins were likely to be a hundred meters or more underwater.

"Let's leave this question until later -" Zhang Xiao stood up and said affirmatively:

"Even if we find a way to reach the ruins safely, we still have to enter the water in the end, so it is necessary to adapt to the underwater environment in advance."

Ron pointed at Malfoy and shrugged:

"But he's already like this -"

The rest of the words were not said, but everyone understood that Malfoy suddenly lifted up the blanket on his body.

It’s okay to be ridiculed by anyone, except Weasley!

"I can!"

"Don't make any noise, like this." Zhang Xiao just thought for a moment, raised his hand and snapped his fingers:

"Uncle Yun."

There was a slight explosion, and the elf appeared in front of everyone, respectfully:

"Master?"

Zhang Xiaoling, who is the executive vice president of Slytherin, took out paper and a brush and wrote a note.

"Give this to Professor Snape."

The content of the note was very simple, asking the dean to give Draco a gillweed so that Draco could adapt to the underwater environment.

If I remember correctly, this kind of grass can help the user evolve gills and webs, and can further adjust the body's adaptability to water temperature, similar to fish.

Yun Bo came back very quickly. The herb is a rare medicinal material, but it is nothing to Snape. The range of use of the herb is very small, but it is difficult to find.

So after seeing Zhang Xiao's request, he gave it without hesitation.

A group of young wizards came to the entrance of the ice cave again. Malfoy suppressed his nausea and stuffed the gill grass into his mouth.

"Ugh - it tastes terrible. It tastes weird, tough and greasy, like the tentacles of an octopus."

Malfoy swallowed the gill grass with difficulty, and the little wizards also swallowed because they watched a lump in Malfoy's throat slowly slide down.

Everyone shivered in the cold wind, waiting for Malfoy to change.

At this moment, Malfoy suddenly felt as if an invisible pillow was pressing down on his mouth and nose.

As soon as he took a breath, he felt like his mind was spinning. His lungs were empty, and there was a sudden sharp pain like a knife on both sides of his neck——

He couldn't help but grab his throat with his hands.

Malfoy's strange movements attracted everyone. They saw two narrow slits under Malfoy's ears, opening and closing in the cold air... He had gills!

“It really works!”

Zhang Xiao kicked Malfoy on the butt, which looked like a fish jumping on the shore.

'Plop!' The water splashed loudly, but soon Malfoy leapt out of the water, jumped upright in the air with a very graceful gesture, and drilled straight through the hole.

It looks like it’s done!

Then everyone jumped into the hole one after another.

The underwater world has a kind of tranquility. In this environment, every sound in the body is amplified.

Malfoy was like a swimming fish, moving flexibly around everyone.

This feeling is so wonderful, breathing in the cold lake water is like getting the oxygen needed for life.

His head was no longer spinning; on the contrary, he was as clear-headed as ever.

Malfoy took another deep breath of water, feeling the water flowing smoothly through his gills and delivering oxygen to his brain.

He stretched out his hands in front of him and looked at them carefully.

They look green and scary underwater, and their fingers are connected by webs. He turned his head and looked at his bare feet—the feet had become longer, and there were webs connecting the toes, as if his feet had suddenly turned into duck webs.