Fred said nothing more, and the pitch-black space fell into an instant silence. Harry cleared his throat, breaking the suffocating quiet.
"So, where does this passage lead? The kitchens?" Harry guessed, figuring only the kitchens would offer such a bounty of rat heads.
At Harry's voice, Fred seemed to breathe a sigh of relief, explaining that the passage led to Honeydukes Sweetshop in Hogsmeade.
"Fred and I often use it to get some butterbeer and sell it to those in need to make a bit of extra Galleons," George added, then continued, "The spell to open it is 'Dissendium'. Harry, can you keep this a secret?"
"I won't tell anyone, except Hermione," Harry promised.
"Of course, you can absolutely tell Hermione. After all, Madam Puddifoot's Tea Shop in Hogsmeade is quite the place," Fred said heartily, nudging George with a mischievous grin. George caught on, grinning back and saying Hermione would definitely love Madam Puddifoot's.
The twins then burst into laughter. Harry, though unsure what significance the tea shop held, had a gut feeling he shouldn't take Hermione to Madam Puddifoot's Tea Shop on the twins' advice. He decided he'd check the library tomorrow to see what shops Hogsmeade had.
Weasleys' Endeavor
Inside the passage, the Weasley brothers began tinkering with the rat heads, while Harry watched. Fred grabbed a rat head, stripping off the skin and meat, while George pulled out a bucket to collect the flesh and blood. Harry curiously asked what they used the blood and flesh for.
"Can't waste it, can we? Fred and I don't have much funding," George said, wiping sweat from his brow.
After a while, Harry sensed that Filch had likely given up on catching them, so he bid them farewell.
"Leaving so soon, Harry? Why don't you head back to the Gryffindor common room with us later?" George asked, looking up.
"No, I still have something to do." Harry declined George's offer, and George, understanding, didn't press him on what he still needed to do.
After leaving the fourth-floor corridor, Harry decided to find an empty room near the Gryffindor Tower. This time, luck was on Harry's side. He easily found an empty classroom and didn't encounter Filch or any patrolling professors along the way.
Unlocking Minds
Pulling out "Unlocking Others' Minds", Harry gave his own mind a good jolt, then successfully opened the book. The first page was an introduction to the Muddle-Headed Charm, and Harry began to study it carefully.
Harry found that the book was written in incredibly plain language, making it so easy that even a simpleton could learn the spell. This, he realized, was the true advantage of pure-blood families; their spellbooks were incredibly detailed. In contrast, the textbooks used by Hogwarts students were quite ordinary, lacking many crucial details (like the difference between the Half-Blood Prince's Potions textbook and the standard one).
Harry sighed in admiration for a moment, then continued reading.
"So that's it! The Muddle-Headed Charm is for helping the learner familiarize themselves with brain structures faster and better," Harry murmured to himself. The book stated that one had to master this charm before practicing Legilimency, otherwise there was a high risk of damaging the victim's brain. Harry felt the charm wasn't difficult, but he couldn't practice it. Hermione had been by his side all day, so Harry hadn't realized he needed fresh brains.
A Library Rendezvous
On Saturday, Hermione went to the library again. In the common room, Harry seized the opportunity to meet with the Weasley brothers.
"Harry, your plan might have to be delayed," Fred said immediately, delivering bad news.
"Indeed, we truly didn't expect Lockhart to have girls trailing him everywhere he goes, like a walking sunflower," George complained.
Harry, however, looked at them skeptically. He felt the Weasley brothers were trying to pull a fast one on him. From Harry's perspective, the Weasley twins, aside from classes and Quidditch practice, spent the rest of their time in the Gryffindor Tower discussing the difficulties they were having replicating the golden skull.
"You've been staying around the tower; are you tracking Lockhart with your minds?"
Faced with Harry's blunt question, Fred replied, "We have special ways of monitoring Lockhart."
"Even if we don't leave Gryffindor Tower, we can see where Lockhart goes," George added.
Just as Harry was about to press further, Hermione walked into the common room, and Fred and George seized the chance to make a hasty exit.
"Hermione, why are you back so early today?" Harry asked in surprise; she usually spent the entire Saturday morning in the library.
"This unicorn hair quill broke, I came back to get another one," Hermione said with a hint of irritation. She didn't seem to notice why the Weasley brothers had run off.
"Hermione, why don't you use a quill made from a phoenix feather?" Harry asked curiously.
Hermione didn't reply, but simply gave Harry a withering look. After getting her quill from the dormitory, Hermione extended an invitation to Harry once more.
"Do you want to come to the library with me? You're just staring into space in the common room anyway. You might as well come to the library and see if there's a way to open that book."
"Alright, wait for me a moment."
"Okay, then I'll see you at the Great Hall for lunch—you're coming with me?" Hermione looked a little surprised, as she expected Harry to refuse as usual.
Actually, even if Hermione hadn't asked, Harry would have gone along. He had only stayed in the common room to meet the Weasley brothers, and now that they were gone, there was no reason for him to remain. Plus, Harry had a bold idea.
Harry returned to his dormitory to grab his suitcase, then followed Hermione to the library. Madam Pince eyed Harry and Hermione, who were sitting by the window, with suspicion. This was because Lockhart often paraded around Hogwarts with a large retinue, even going so far as to offer unsolicited advice to couples by the Black Lake. Consequently, many couples had recently been using "studying" as an excuse to rendezvous in the library.
But Madam Pince watched for a while and saw that Harry and Hermione were both diligently reading their books, without any untoward behavior. So she shifted her attention to other students.
Back to Harry, he was discreetly writing notes and passing them to Hermione.
"Why is Madam Pince staring at us?"
"Are the people at that table across from us really here to study?"
...
At first, Hermione responded diligently, but the increasing number of notes began to annoy her. She couldn't concentrate on her studies!
"Madam Pince is gone. I want to check out the Restricted Section. Keep watch for me."
Seeing another note from Harry, Hermione was about to lose her temper, but the information on it shocked her. She looked up, and Harry had vanished, leaving only his suitcase forlornly on the seat.
No wonder he brought his suitcase, it was for the Invisibility Cloak, Hermione thought, gritting her teeth, as she was forced to cautiously monitor Madam Pince's movements.