However, even as night fell, Severus and the others remained empty-handed.
They found no trapdoors, cellar entrances, or any sign of one. Severus even went to find Kingsley at one point, borrowing a Niffler from the Department for the Regulation and Control of Magical Creatures to help search underground, but still found nothing.
It was as if Sirius's deduction was completely wrong, and the Fawleys simply didn't have a wine cellar at all.
"Who says a pure-blood family must have a wine cellar for storing wine? I hear the Weasleys are quite poor. Do they have a wine cellar?" Lockhart's question made Sirius irritable.
"Is your head made of troll brains? Have you ever been to the Weasley house? If you had, you'd understand why they couldn't have a wine cellar! But we're standing before the Fawley manor right now! From the perspective of a pure-blood family or any other angle, dare you say a large estate like this wouldn't have a wine cellar!"
Severus didn't join their argument. He simply raised his wand.
"Instead of guessing here, we might as well go ask someone directly. Given Muriel's connection to the Fawleys, she definitely knows whether a wine cellar exists or not."
Soon, Severus and the others returned to the Prewett house and found Muriel again.
Faced with their question, the brash old woman quickly provided an answer.
"The Fawleys didn't like drinking, but they were magical historians! The original wine cellar in their home was used by them for researching ancient magical artifacts! Weren't you at their house? You should have found it easily!"
At this point, her expression towards the two-men-and-a-dog trio grew suspicious, clearly doubting their professionalism.
Severus didn't care what she thought. He and the others returned to the Fawley house.
"Now that we've confirmed the Fawleys absolutely had an underground room, but we can't find the entrance, and there's no trace of it underground either... someone hid it with magic."
"But ordinary magic can't achieve that level of concealment," Lockhart said. Though he was useless in most areas related to Memory Charms, as a Ravenclaw graduate, he was no ignorant fool.
At that moment, a light flashed in Sirius's eyes. He looked up. Three pairs of eyes, of two men and a dog, met, and in the next instant, they almost simultaneously uttered a spell.
"The Fidelius Charm!!"
"Exactly! It can only be that! Only that spell could achieve this!"
"As long as this charm exists and protects a location, unless we find the Secret Keeper and hear the location directly from them, we'll never find it in our lifetimes!"
They had identified the key protective charm, but an even bigger problem immediately followed.
"Who could this Secret Keeper be?" Lockhart asked first.
Sirius, however, already seemed completely unconcerned.
"Whoever it is, they won't be easy to find. So, I say we should just give up on this matter now, let the girl quietly receive treatment at St. Mungo's..."
However, before he could finish, Severus had already slapped a stack of letters in front of them.
"These were found in the study on the second floor. The writer is clearly a close friend of the Fawleys!"
Sirius didn't look at the letters. He was immediately skeptical.
"Even the closest friend might not necessarily be privy to something like this."
"They and this friend of theirs plotted together how to leave the Death Eaters," Severus said softly. "With a relationship that close, even if this person isn't the Secret Keeper, they must know something."
Lockhart, who had already skimmed a few letters, interjected,
"But these letters aren't signed. We don't know if this friend of theirs is alive or dead, or even who they are."
Severus precisely pulled out one specific letter from the stack.
"We have no way of knowing the writer's identity from these. But in this letter, he mentions someone… someone both the Fawleys and the letter writer knew!"
This time, both Lockhart and Sirius saw the name Severus pointed to-
Karkaroff.
…
The northern European school of Durmstrang entered its harsh winter earlier than Hogwarts.
Compared to the recent turmoil and unrest in Britain and France, this place, though bitterly cold, seemed aloof and detached from the world.
However, as Headmaster of Durmstrang, Karkaroff's mood hadn't been very pleasant lately.
Many students and teachers noticed he would often pace back and forth in his office, frowning deeply, sometimes even with a look of sheer terror on his face, muttering to himself… 'It's impossible, he can't be back...!'
And as more news from Britain arrived, he appeared to become remarkably relaxed, as if his entire being had found solace, wearing a look of unprecedented ease and a smile.
This was quite unusual, even rarer than his previous reactions.
Just as Durmstrang's students were marveling at their Headmaster's recent changes, three uninvited guests suddenly visited on this day.
When the Durmstrang's caretaker led Severus and the others to the Headmaster's office, Karkaroff couldn't stop staring at his former 'comrade'.
His eyes were like a pair of searchlights, continuously scanning Severus up and down.
This kind of reception made Lockhart feel uneasy. He instinctively shrank back until Severus spoke.
"I know what you're trying to see on me, Igor." Severus met Karkaroff's scrutiny head-on, speaking with a faint smile.
"You've heard what happened in Britain. You felt his summons too, didn't you? You're unsure of my purpose here today, uncertain who I truly represent!"