Sean passed through there and returned to Hope Nook.
Mr. Owl was unusually quiet today; instead, he opened the door for him right away.
Inside Hope Nook, the fireplace crackled cheerfully, and the wooden bookcase kept reassembling itself, sorting Sean's books into categories.
Sean knocked on it. The planks shifted and rearranged, and a Pensieve was spat out.
Silvery threads churned within. Sean bent over the Pensieve.
In an instant, his feet left the ground…
He fell through darkness again, dropping into memory after memory.
"Ravenclaw's…"
When he pulled free of the memories and returned to Hope Nook, he went blank for a moment.
He couldn't remember what Ravenclaw had left behind.
Hufflepuff's Cup, Gryffindor's Sword, Slytherin's Locket… but what did Ravenclaw leave?
He drew up a strand of silver memory, and the Sorting Hat's voice surfaced in his ear:
"Of course, of course—the diadem of surpassing wisdom, the cup brimming with sincerity, the sword summoned by courage—"
Ravenclaw had left a diadem…
But why couldn't he remember it?
The moment he recovered the word, related memories surged up as well—
yet it was all still separated by a hazy, gray film.
He frowned hard and looked up. Mr. Owl's portrait had somehow shifted inside, and was staring at him with wide, hopeful eyes.
The second Sean noticed him, Mr. Owl's portrait immediately slipped back outside.
"Mr. Owl?" Sean called.
"Clever little wizard…" Mr. Owl muttered over his shoulder, then went perfectly still.
Sean watched him for a while… Mr. Owl was acting too strange today.
But Mr. Owl clearly wasn't going to say anything, so Sean could only keep digging at the idea of Ravenclaw's diadem. Had he simply forgotten?
There was a way to find out—
Occlumency.
Whether some unknown magic had interfered with his memory, or he'd truly forgotten, Occlumency could help him recover more detail.
…
Older students were already leaving Hogwarts in groups, and everywhere in the corridors younger students pressed up to the windows, watching in envy.
Sean held his plan map—at the location marked for the staff room, a red exclamation mark lit up.
Beneath it, a line of runes read:
[Professor Flitwick — Undetectable Extension Charm]
This weekend, Sean could learn the Undetectable Extension Charm from Professor Flitwick, to support him in making expanded-capacity storage items.
Flitwick was easy enough. But Occlumency?
Sean knew that someone who truly mastered Occlumency was an Occlumens.
Known Occlumens included: Albus Dumbledore, Gellert Grindelwald, Voldemort, Horace Slughorn, Severus Snape, Barty Crouch Jr.…
So—could he learn it from Snape?
And if Sean told Snape he wanted to learn Occlumency, how would he explain why?
Thinking it through, he arrived at the place he'd arranged with Flitwick—
the staff room.
It was a long room meant specifically for faculty to rest in. Two talking stone beasts sat at the entrance. Inside, the walls were paneled in wood, and mismatched old black wooden chairs filled the place.
Professor Binns was there too, resting—waiting until next week when he'd stand up and go teach again.
Well… the same routine for a few centuries now.
"Professor Flitwick."
Sean knocked.
"Come in, child."
The voice wasn't Flitwick's—it was one Sean knew well.
"Professor McGonagall."
Sean's steps quickened.
"Learning the Undetectable Extension Charm takes a great deal of patience," McGonagall said, holding a cup of red tea. Steam misted the air in front of her square spectacles.
"Yes, that's right. Come along, Mr. Green!" Flitwick said warmly, pulling Sean inside. "I'm not surprised at all you want to learn this charm—but tell me, child: what is the Undetectable Extension Charm?"
"The Undetectable Extension Charm expands an object's internal capacity without changing its outward appearance, and reduces its weight.
"When cast, it often requires a sealed container and supporting magical materials to maintain the effect.
"As for the principle—it works by restructuring spatial dimensions to achieve geometric volume expansion."
Sean paused for two seconds, then answered.
"Splendid!" Flitwick nodded in satisfaction.
"And you should also know that privately applying such a charm is a serious offense; violators risk imprisonment in Azkaban," Flitwick added.
Sean understood. The Undetectable Extension Charm lets an object keep its original external size, erasing spatial anomalies to evade magical detection.
Which meant—without strict control, illegal large-scale concealment would become commonplace.
Not good for the stability of the wizarding world.
"However, Ministry approval is quick," Flitwick said with a smile, handing Sean an approval form.
That genuinely surprised Sean—he hadn't expressed interest very long ago.
Flitwick had deep experience in Charms, and under his guidance, even with only a "blue" talent, Sean learned quickly.
Before long, he had the trick of it.
"Undetectable Extension!"
With a flick of his wand, the inside of a paper box seemed to shift violently. If you slid a finger in, you'd find that a box not even as long as a finger could swallow the whole thing.
[You practiced the Undetectable Extension Charm to an apprentice standard. Proficiency +1]
[Undetectable Extension Charm: Locked (1/30)]
Holding the paper box, Sean's eyes curved with a faint smile.
Once something was on the panel, the only real obstacle left was time.
Even so, the box quickly returned to normal—because there were no supporting materials.
And to make a lasting expanded object, the most important material was Occamy skin.
In the staff room, Sean's plan map popped out on its own. A sky-blue quill scratched rapidly, adding another plan.
Flitwick stared at the dense web of locations and folded-up plans—and couldn't help blinking, stunned.
Then he let out a helpless laugh.
"Is that your plan for half the term, Mr. Green?"
"It's not…" Sean said without thinking as he put the plan map away. "It's for a week, Professor Flitwick."
And even after Sean left the staff room, Flitwick was still a little dazed.
"Minnie… oh, you gave him that?" Flitwick turned and asked.
"That's the problem, Filius," McGonagall said, warmth like firelight in her eyes. "I haven't had the chance yet."
She knew it well: someone would always keep walking, slowly, down the road they'd chosen.