"Hey, the owner isn't here—"
Hearing the commotion, Professor McGonagall turned around and sighed somewhat helplessly.
"Relax."
William gestured reassuringly with his hand, then landed on the ground and fished out two Sickles from Lupin's pocket, tossing them onto the counter—was he the kind of person who wouldn't pay for what he consumed? No! Having eaten a bowl of noodles, he should pay for a bowl of noodles, it's the rule!
"We have to think of a way to seal this secret passage... Sirius also knows about this place, right?"
Looking at the Hogsmeade streets outside the window, Professor McGonagall scanned the area, then turned to Lupin, asking seriously.
And at the moment he heard Professor McGonagall's question, Lupin also realized the severity of the issue—
He knew about this secret passage, and Sirius was the first to discover it, even bringing the three of them together. Every full moon afternoon, the other three Marauders would accompany him through this passage to the Shrieking Shack on the other side of Hogsmeade.
So, even today, could Sirius have infiltrated the castle through this secret passage?
"Seal it up?"
William pondered as he started matching the tickets on the register, stuffing candy worth two Sickles into his pocket, "No, no need to seal it." He shook his head, denying Professor McGonagall's proposal.
"If you seal it, how can you fish?"
After speaking, William explained his reasoning to the two, "If Sirius really entered the castle from here, this time he left empty-handed, didn't even enter the Gryffindor Common Room—he's definitely going to come back."
"If he really is, as you say, a Voldemort fanatic." William added.
"Fishing... wouldn't that be too dangerous?"
Hearing William's statement, Professor McGonagall couldn't help but furrow her brow—
She was still more inclined to directly seal the entrance, fundamentally eliminating the potential threat of Sirius infiltrating the castle. After all, he was a dangerous criminal, and if he came into contact with the students... the consequences would be unimaginable.
"Speaking of which, Remus, are there any more secret passages like this?" William furrowed his brow and looked at Lupin.
"Yes, yes, there are 7 similar secret passages in the castle, although some of them might have collapsed—without exception, he knows their locations very well." Lupin nodded, stating seriously.
"Are we going to seal them all?"
William nodded, unsurprised, knowing of at least four himself—compared to him, the "Marauders" knew even more secret routes. "Even if all are sealed, once Sirius finds out, he'll find other ways or simply go into hiding—"
"..."
Professor McGonagall frowned, William's speculation seemed logical—a criminal hiding poses an even greater challenge, and ultimately, this is just a school. Eventually, Harry would have to return home, and if Sirius remains in hiding until then, should they ever let their guard down... "So, what do you plan to do?"
"Simple, set up an alarm system, something like a Sneakoscope."
William shrugged, after contemplating for a moment, then as if he suddenly recalled something, reached into his pocket and pulled out Niffler, shaking its legs. A pile of shiny potion bottles, coins, jewelry, and stone slabs rolled out of Kabuda's belly.
"Squeak squeak!!!"
Woken from its slumber, Kabuda looked at its scattered "treasures" on the floor and let out a sharp burst of sound.
"...Is that my hairpin?"
Surveying the mess, Professor McGonagall squinted her eyes, then reached out, and a glowing hairpin floated into her hand.
"Ahem, don't mind these details, what I mean is this."
William coughed twice, breaking the awkward atmosphere, and then rummaged through the scattered stones for a moment before grabbing one and pointing to the twisted deep blue patterns on it, "This is a combination of surveillance and alarm runes, its function is to monitor certain places, once something happens at a monitored location—"
William didn't finish his sentence, but the other two clearly understood his point.
"Is this... reliable?" Professor McGonagall still appeared a bit uneasy.
"...Perhaps we should go back and talk to Headmaster Dumbledore, let him decide?"
Finally, Lupin opened his mouth to suggest, and both William and McGonagall exchanged glances, then nodded—Lupin made a good point.
...
...
"...Alright, Severus, I also figured Blake wouldn't linger in the castle."
"But have you considered how he got in, Professor?"
In the purple sleeping bag, Harry lay with his eyes closed, carefully listening to the voices not far away, recognizing that the person speaking was Snape. At this moment, Dumbledore had just finished his conversation with Percy, and before he could leave, Snape walked in from outside the Great Hall—
Harry raised his head slightly from his arms so that his other ear could listen too.
"Many ideas, Severus, but none of them stand on solid ground."
Harry squinted his eyes, peering towards where they stood. He saw Dumbledore with his back to him, Percy's face visible, standing beside the headmaster, fully focused, while on the other side, Snape paced angrily.
"Do you remember our conversation, Headmaster? You haven't forgotten, have you? It was—er—right before the start of the term?" Snape spoke with barely moving lips, his gaze shifting as though he didn't want Percy involved in their conversation.
"I remember, Severus."
Dumbledore replied, a hint of something akin to a warning in his voice.
"Blake entering the school unaided? That seems—impossible, and I have expressed my concerns when you appointed—"
"I do not believe there's anyone in this castle who could or would help Blake enter."
Dumbledore interrupted Snape's angry, low voice of doubt, his tone leaving no room for further discussion. Snape clearly didn't look pleased, but he nodded, leaving the subject closed.
"Now, I must go find those Dementors," continued Dumbledore, "I said I'd notify them once we finished our search."
"But weren't they coming to help…"
Percy's question was cut off by the reopening of the Great Hall doors, and at the sound, Harry turned in that direction again, eyes narrowed to see the group entering—it was Professor McGonagall, with Professor Lupin and William following behind her.
"Minerva—"
Seeing the trio, Dumbledore approached them immediately.
"No discoveries, Professor—Blake should have left, but we discovered a secret passage."
Professor McGonagall's voice was kept low. Harry had to inch forward slightly to catch a few of the floating syllables in his ears.
"It leads to Hogsmeade..., Dumbledore, I have a plan..."
This was William's voice, but he couldn't hear more. Harry cautiously opened his eyes further, but by then William had already approached Dumbledore's side.
"...Are you sure about this?"
Harry saw Dumbledore furrow his brows, appearing somewhat conflicted.
"Block... unblock, Professor, you have to... how can there be... catching a thief...?"
William nodded, made a hand gesture Harry couldn't interpret as he watched from his reversed perspective.
"...We should discuss this outside."
Dumbledore paused for a bit, then led the group out.
As they left the Great Hall, Harry listened to the whispers of nearby ghosts. He looked at Ron and Hermione beside him; they too had their eyes open, gazing at the starry, twinkling ceiling.
"What on earth is going on?"
Ron mouthed silently, his lips moving without a sound.