Hogwarts: Lacus doesn't want to be a witch who destroys nations.

Lux tiptoed back to her dorm room, where her roommates were already fast asleep. Lumi poked her head out of the wicker basket and yawned widely: "Sis, I told you that Forbidden Forest was weird, wasn't it? We almost got slaughtered this time..."

"Shut up, Lumi," Lux said irritably, using a cleansing spell to wash the dirt and her robe. "That's called a strategic retreat! Don't you understand? Once I reach level six, I'll buy a Heartsteel and blow it up."

She threw herself onto the four-poster bed, and with a pull of the curtains, shut herself out of the outside world.

But his mind couldn't stop thinking about that deep, dark lake.

LeBlanc said the rune is at Hogwarts, and there are bark trolls deep in the Forbidden Forest that reduce sanity. They searched the castle thoroughly but found nothing. So the most suspicious place is the bottom of the lake.

The charred student at St. Mungo's, the fire at the bottom of the lake that Mia mentioned, the abnormal water temperature... all the clues point to that place.

"Underwater breathing... underwater breathing..." Lux muttered to herself, "I can't really turn myself into a fish, can I? That would be too undignified, and what if I can't turn back? I'd only be able to eat seaweed from now on..."

Lux drifted off to sleep amidst her jumbled thoughts.

In the days following her return from the Forbidden Forest, Lux behaved much better at Hogwarts, at least on the surface.

She attends classes on time every day, actively answers questions, and earns points for Gryffindor, displaying the demeanor of a model student.

As soon as get out of class ended, Lux plunged into the library. Professor Slughorn's badge was really useful; Lux could move around freely and read all kinds of books.

After searching through all the available information, Lux sadly discovered that the magical community seemed to be generally pessimistic about the idea of ​​"allowing wizards to move freely underwater like fish for extended periods of time."

It's either a temporary solution that consumes a huge amount of resources and carries extremely high risks, or it requires special racial talents.

"Am I supposed to ask Dumbledore for a Bubble Charm? That would be so stupid, it's practically the same as turning myself in..." Lux slumped onto the table, her face pressed against the cold parchment, feeling utterly hopeless about the future.

"Lux? Are you alright?" a gentle voice sounded beside her. Lux looked up and saw Miranda Goshak holding a stack of books, looking at her with concern. "You look like you've been trampled by a troll."

"Miranda!" Lux cried out as if grasping at a straw, sitting bolt upright. "Help! I need to breathe underwater, for a long time. Is there any efficient way with fewer side effects?"

Miranda put down her book, sat down opposite her, and frowned slightly. "Living underwater for an extended period? That's not within the scope of first-year Charms class. What are you trying to do?"

"Uh...you want to eat fish, don't you?" Lux mumbled. "Anyway, it's very important, extremely important!"

Miranda thought for a moment, her fingers unconsciously circling on the table: "Let me think... Theoretically, there is an alchemical artifact called the 'Bubble Head Amulet,' which can create a small, closely attached magical field that continuously supplies fresh air to the head and can filter impurities and even some magical toxins from water."

Lux's eyes lit up instantly: "This is it! Senior, can you make it?"

Miranda shook her head, a hint of regret on her face: "Unfortunately, I've only seen related records in 'Applied Alchemy.' The crafting process for this kind of amulet is very complicated, and Hogwarts currently has no plans to teach it. I'm afraid only the professors might be able to make it."

Lux scratched her head: "Is there any other way?"

Miranda shrugged. "That's the closest I can think of to what you're asking for, or... how about you try using Transfiguration to turn yourself into a fish?"

Lux said goodbye to Miranda dejectedly. The bubble head amulet sounded nice, but it would take a long time to learn how to make it now.

Should we really go find Old Deng? No, that's too suspicious.

She wandered aimlessly through the castle and unknowingly ended up near the Transfiguration classroom.

Just then, I saw Minerva McGonagall walking out of the classroom carrying a stack of homework.

McGonagall was now a Gryffindor prefect, renowned for her rigor and exceptional talent in Transfiguration.

"Senior Mag!" Lux had a sudden inspiration and quickly ran over to greet her.

McGonagall stopped and looked at Lux with some surprise: "Lux? Is something wrong?" She was quite impressed with this first-year wizard, especially her desperate efforts to earn points for Gryffindor.

This is quite rare in Gryffindor; they haven't won the Academy Cup in a long time, but this year they seem to have a good chance.

"Senior, I'd like to ask you a question about Transfiguration!" Lux tried her best to make her expression look like she was eager to learn.

"If, and I mean if, someone wants to stay underwater for an extended period of time, besides the head-diving spell, what other transfiguration spells could be used, like turning oneself into a fish?"

A glint flashed in McGonagall's eyes as she sized Lux ​​up and down. "You want to explore the Black Lake? Lux, I must warn you, it's dangerous there now. The headmaster has explicitly forbidden students from going near it."

"No, no!" Lux quickly waved her hands. "I'm just curious! Purely academic discussion! Doesn't shapeshifting allow you to change your form and adapt to your environment? If I turn into a fish, can I breathe underwater?"

McGonagall's expression softened somewhat. After a moment's thought, she said, "Theoretically, it's possible. Becoming an Animagus would allow you to do this. Historically, there have indeed been wizards who successfully transformed themselves into aquatic creatures to adapt to the underwater environment."

"The most famous example is Mirabella Plunkett, the 19th-century witch who fell in love with a mermaid living in Lomond Lake. After her family objected, she transformed herself into a haddock permanently and disappeared."

Lux listened, stunned. "Permanently turning into a fish? Can you turn back?"

"Mira Bella didn't turn back." McGonagall's voice carried a hint of warning. "High-level Transfiguration, especially permanent transformations across species, is extremely risky. Even the most top Transfiguration masters, like Professor Dumbledore, can easily turn water into breathing oxygen or change their own form to adapt to the environment, but that requires unparalleled control of magic and a profound understanding of the nature of Transfiguration."

"For ordinary wizards, especially younger students, attempting this kind of transformation is tantamount to suicide. You might lose yourself, be trapped in the form of a fish forever, or worse."

McGonagall paused, her tone serious: "Lux, I understand your passion for magic, but please be grounded. Polymorph is a delicate and dangerous spell; don't be overly ambitious."

"If you are really interested in the underwater environment, I suggest you first thoroughly understand 'Intermediate Transfiguration' and 'Fundamentals of Human Transfiguration,' and at least become an Animagus before considering this issue."

By the time we become Animagus, the Void might have already invaded.

Lux inwardly groaned, but outwardly nodded obediently, "Thank you, senior! I understand, I'll work hard on my fundamentals!"

After saying goodbye to McGonagall, Lux felt even more desperate. She couldn't find the incantation for the Bubble Head Charm, and learning the Bubble Head Talisman would take a long time. Transfiguration would require at least a year's worth of planning. Did she really have to go to Dumbledore...?

Lux was walking down the corridor when she bumped into Professor Slughorn, who had just come out of his office.

Professor Horace, beaming, greeted Lux ​​warmly upon seeing her: "Lux, my child! I've been looking for you! Come and see this!"