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

"Old Fu, this is it." Lux pulled her cloak, which reeked of the suspicious stench of the sewers, tighter around herself, and pointed furtively at the wall. "The entrance is behind this wall..."

Before she finished speaking, Holmes's grey-blue eyes had already landed on a few bricks on the wall.

"Interesting..." Holmes's voice was deep. "This time I can see the Leaky Cauldron clearly. The concealment spells against Muggles should have been fixed, but I can still notice this pub."

"Uh..." Lux blinked and offered her insights on the old detective's doubts, "Either you have exceptionally good eyesight, or you, Old Sherlock, are actually an undiscovered wizard, or a Squib."

Holmes didn't answer directly, but instead smiled almost imperceptibly. "Come on, Miss Lina, let me see your magical world."

He naturally switched back to the hunched, coughing, and cloudy-eyed "dumb grandpa" mode, shuffling behind Lux ​​with faltering steps.

"Indeed, if you're going to put on an act, you have to go all the way, otherwise it would be troublesome if Boginbock and that Fenrir were in cahoots."

Lux took out her wand and expertly tapped the specific bricks.

The brick wall slid open quickly to both sides, revealing the bustling Diagon Alley behind it.

The two seemed to pass through an invisible curtain, stepping into Diagon Alley through the back door of the Leaky Cauldron.

The moment he stepped inside, Holmes seemed to be put on pause.

He stood stiffly on the cobblestone road, leaning on his cane, his cloudy eyes widening instantly, filled with childlike shock and pure curiosity.

In the shop window, automatically knitting needles danced like serpents; a broom floating in the air displayed a flashy flight path, nearly hitting a passerby on the head; in the cauldron shop, a uniquely shaped cauldron was "popping" out colorful bubbles, which turned into hopping chocolate frogs after landing; at the entrance of the owl post office, a dozen owls perched neatly on a shelf, tilting their heads to observe passersby, one of them giving a loud "coo" to Sherlock Holmes; further away, in front of a pet shop, a cage of brightly colored fluffy owls rolled around like fluffy balls, emitting soft purring sounds.

The hustle and bustle, colors and chaos of the magical world instantly assaulted the senses of this great detective who had devoted his life to logic and empirical evidence.

"This..." Holmes's voice was somewhat surprised.

"This is amazing." He instinctively wanted to take a look, but stopped abruptly when his fingers touched the coat pocket, forcing himself to pull himself out of the shock and tightening his numb expression as "Grandpa Squib" again.

"You'll get used to it, old man, you'll get used to it." Lux suppressed a laugh, trying to make her tone sound like she was comforting a country bumpkin who had never seen the world.

"That's how magic works, it's basic stuff." Lux bought a handful of candy from a roadside stall and took the opportunity to slip Holmes a piece of sizzling honey candy. "Here, calm down, sweets help relieve cognitive shock."

Holmes looked at the brightly wrapped, slightly trembling candy in his hand, his lips twitched slightly, but he finally unwrapped it and popped it into his mouth. A strong, electric-like sweetness exploded on his tongue, making him involuntarily raise an eyebrow.

When the two finally stood before the gloomy, narrow entrance to Knockturn Alley, Holmes had largely regained his composure, though the depth of his gaze and curiosity remained undiminished.

"Old Fu... uh, Grandpa," Lux whispered, "Knockdown Alley is just ahead, it's more exciting than Diagon Alley... um, stick close to me."

The air in Flip-Over Alley was like solidified, low-quality grease, filled with an indescribable mixture of bloody and malicious sweetness.

The shop windows on both sides were mostly covered with thick dust, displaying some unsettling items: dried human hand candles, slowly wriggling eyeballs in glass jars, and magic chains emitting low whimpers... Pedestrians were few and far between, and most of them hurried along, their faces hidden behind hoods or scarves, their eyes wary and indifferent.

Based on the information provided by Fenrir, the two quickly located the "Boking-Bock" antique shop.

The shop was dilapidated, and most of the gilded lettering on the signboard had long since peeled off. Above the door hung a huge crystal ball covered in cobwebs, inside which seemed to be a smoke creature that was constantly changing shape.

Pushing open the creaking wooden door, an even stronger smell of dust and preservatives hit you. The shop was extremely dimly lit, with only a few floating oil lamps burning with eerie green flames for illumination.

The shelves reached to the ceiling and were crammed with all sorts of strange and even creepy items: an ornate hand mirror inlaid with human teeth, a set of exquisite teaware that looked like it was made of human bones, a gemstone necklace that kept oozing dark red liquid, and a mummified corpse in a glass jar, gently tapping the jar's walls with its finger bones.

A sallow-faced shop assistant silently slipped out from behind a row of jars containing twisted specimens.

He had a pair of dull, lifeless eyes with puffy eye bags, and a professional, cold, fake smile on his lips.

"Welcome to Borgin-Bock, gentlemen," the clerk's voice was like sandpaper scraping. "See if there's anything we can do for you? Our products are of the highest quality and fair." His gaze lingered on Lux's fluorescent green hair for a moment, a barely perceptible hint of mockery flashing across his eyes, before sweeping over Holmes and, after confirming that he was just a harmless old Squib, losing interest.

"Ahem... Hello," Lux tried her best to imitate a timid, naive werewolf, "We... we want to find Mr. Collector to buy... buy something."

"A collector?" The clerk's sallow face remained expressionless, but his tone was clearly impatient.

"He's here today. But he doesn't see just anyone. What do you want?"

"We want that opal necklace," Lux replied.

The shop assistant raised his eyelids slightly, a hint of understanding flashing in his cloudy eyes, followed by even deeper contempt.

"Ah, that necklace..." he drawled.

"The price of a collector's consignment item..." he slowly extended his withered finger, "Sixty-eight Galleons."

"Sixty-eight Galleons?!" Lux nearly cried out. She only had less than eight Galleons left of Dumbledore's scholarship. "That's way too expensive!"

The shop assistant shrugged, his sallow face screaming "Don't block my way, you poor wretch!" "Mr. Bokin and the collector set the price; I'm just the shopkeeper. Can't afford it? There are cheaper items over there."

He casually pointed to a pile of dusty things in the corner that looked like broken wand heads and dried animal carcasses, "Or... go outside, turn left, and rummage through the trash can?"

Lux's heart sank. It was over; this path was blocked.

Her mind raced, deciding whether to steal from Gringotts, rob some Galleons, or simply use a spell to knock out the clerk and run off with the loot? After all, double-crossing in Rumblehouse is pretty common, right?

Holmes pulled a bulging leather wallet from the inside pocket of his worn-out overcoat. Inside, instead of glittering Galleons, were thick stacks of pounds sterling with the Queen's image on them.

"Can I pay in pounds?"

"Pounds?" The shopkeeper scoffed. "Bogin-Bock only accepts Galleons, or magical items of equivalent value. Muggle paper is too rough to even wipe your butt with."

"Where can I exchange pounds for Galleons?" Lux asked eagerly.

The shop assistant looked at her like she was an idiot: "Diagon Alley, Gringotts, Fairy Bank. But..."

He glanced at Holmes. "Taking so much scrap paper to Diagon Alley? Good luck, don't get robbed of everything, not even your underwear." He smiled maliciously and turned to leave.

Lux, supporting Holmes, quickly left the suffocating little shop of Borgin-Bock.

As soon as Lux stepped out of the store, she immediately started complaining: "Damn! 68 Galleons! What a heartless boss! Is this damn necklace made of gold?"

Holmes quickly shed his facade of old age and helplessness, though his steps remained slow.

"Gringotts's Fairy Bank... its currency exchange system... interesting. On what basis is your financial system built? Precious metal standard? Magical contract credit? Or... pure military intimidation?" he muttered to himself.

The two navigated the labyrinthine upturned alleyways until they found the imposing Gringotts Bank building.

Before the bronze gate stood a guard in a scarlet, gold-trimmed uniform, his expression haughty. Holmes, once again in "dumb grandpa" mode, shakily walked into the bank with Lacus's support.

The exchange went exceptionally smoothly. When Holmes placed the thick stack of pounds in front of the tall counter, the shrewd-looking fairy teller behind it, wearing gold-rimmed pince-nez glasses, simply fiddled with it a few times with her long fingers, scanned it briefly with a small, emerald-encrusted instrument, and then announced a number with an extremely low conversion rate.

Then a small bag of jingling Galleons was pushed over. Throughout the entire process, the fairy's gaze didn't linger on the two of them for long, as if they were just two walking packages.

"No, the pound has fallen again?"

The fairy teller, without even looking up, replied, "The bank has a very low opinion of the current Muggle government; their currency might become worthless in a few years."

"It's so dark!" Lux stormed out of the bank, her green hair making her look like a green pufferfish.