The Bubble-Head Charm That Caught His Eye

"Huff... huff..."

Beside the Black Lake, Andrew slowed from a run to a brisk walk and shook his head at the crowd packed along the shore.

It was already November. Shouldn't people be sleeping in at this time of year?

How did this lot have more energy than he did?

The school had never issued an official denial, so Magical Legends remained popular at Hogwarts. Every new issue sent its popularity soaring again.

While Andrew worked hard on his Transfiguration, the other students had hardly been idle. Wave after wave descended on the empty classrooms, and the boundlessly energetic first-years had pestered the portraits beyond endurance.

Even the castle ghosts had all but stopped showing their faces. The latest issue finally gave them some relief: a rumor had spread from who knew where. Its versions varied, but every one pointed to the Black Lake as the place to look.

Some said Slytherin's legacy lay there. Others claimed traces of a great battle remained on the lakebed, while still others insisted Dumbledore's extracted memories were down there. As a result, the shore had been busy day and night lately.

Andrew had no plans to go after anything in the Black Lake. Who knew whether there was anything to find? Even if there was, he was better off spending the time practicing Transfiguration.

There was one thing he envied, though. Quite a few of the older students gathered by the lake had transparent bubbles around their heads. Once they had found some way to keep warm, they could plunge in and search for whatever treasure might be down there.

"I think I've heard of a spell like that..."

He watched the students enter the water and made up his mind to ask an older student for it. A spell this widespread was hardly going to be a secret.

"Oh, you mean the Bubble-Head Charm?"

When Andrew found an older student who had just finished class, the student looked at him in surprise.

"What do you want that spell for? Don't tell me you believe those stories too."

"No. I just think it might be useful."

"Well... maybe it could protect you from whatever those little vendors are in such a hurry to splash around?"

The student shrugged. "I don't know it myself, but wait here a moment. I know someone who's studied it."

About five or six minutes later, Andrew finally had a rough understanding of the Bubble-Head Charm.

The spell was not particularly practical. It created a transparent bubble around the caster's head, allowing them to move through places where the air was poor.

It offered little defense, could not be used to attack or curse anyone, and had few everyday uses. After a few days of popularity, students had mostly forgotten it. It had only caught on in the first place because Peeves kept throwing things around and everyone wanted to protect their faces.

"Explorers learn it now and then, but Human Transfiguration is more convenient in harsh environments. There are potions for that sort of thing, too. Some smugglers have improved the spell, but they're certainly not going to share their magic."

After that brief explanation, the student gave Andrew a piece of parchment bearing the incantation and wand movements. "It's a charm for older students, but have a look if you want to study it. I'll probably have graduated by the time you can cast it..."

"It's a completely different approach..."

Andrew looked over the spell on the note. The explanation was absurdly brief—not the incantation itself, but everything that came with it.

Unlike the lower-year textbooks, which practically took each charm apart piece by piece, these notes seemed to assume he already knew how to cast with a wand and maintain a spell.

Put plainly, casting it seemed to require Charms Fundamentals at level 9, Wand Movements at level 7, a talent for sustaining spells, Spell Manifestation at level 5...

All those prerequisites were things students were expected to pick up along the way. Only after the basics had become instinct through spell after spell could a simple incantation and gesture produce this not-so-simple magic.

"This isn't a spell younger students can master—no, if someone broke it down the way they do the spells taught in lower years, it might not be that hard..."

"But who would put it in the basics? Like that older student said, it's neither representative nor useful as a foundation for other spells..."

Andrew rolled his eyes. Professor Flitwick certainly would not do it. With so many students venturing into the Black Lake lately, he was hardly going to break down a spell that would encourage them and teach it to first-years.

Studying it on his own would get him nowhere. He had put some effort into Charms, but at best he was a good first-year, not even among the very best. Research was out of the question.

"But I still want to learn it... Being able to go underwater would be good enough on its own. It'd be useful for surviving accidents and extreme conditions, too..."

Hiding underwater was a classic way to stay alive, and he knew it all too well. If he could master the spell with a little time, it would be worth it.

"And if I learned it, surely I could even dive in to rescue someone without anything going wrong..."

He sighed, pushed the memories rising in his mind aside, and started thinking fast.

"Mastering the Bubble-Head Charm outright is too difficult. But if I use what I already know..."

His knowledge of Transfiguration was the best tool he had. "The Bubble-Head Charm essentially creates a tough bubble around the caster's head..."

"But I could get the same result with a transparent covering, something like glass but shaped to fit more closely..."

"The difficult part is that the Bubble-Head Charm provides far more air than the bubble appears to hold. From what I've heard, it lets an ordinary person make a round trip to the bottom of the Black Lake..."

"So does it compress the air? That doesn't seem right. Or does it filter it somehow?"

"If it's compression, could I Transfigure the air itself? No—I'd need to Transfigure it repeatedly... Or use some trick to turn the weakening bubble back into air without letting it collapse?"

"If it's filtration, though... that's much harder..."

"But where am I going to find someone willing to help me study exactly how the Bubble-Head Charm works?"

"I can't ask Professor McGonagall... She definitely wouldn't want me spending time on something that would help me break the rules at the Black Lake."

"I've got it!"

Something from a while back suddenly came to mind: someone had paid people to look up information in the library.

It was hard to find someone willing to help as a favor, but there was an efficient way to ask that the other person would welcome.

"Ah, sorry, Dumbledore... Now I have a way..."