Upon hearing Severus's words, Lupin quickly understood.

They had come with Dumbledore's letter of introduction to meet Nicolas Flamel, and Dumbledore and Flamel were friends themselves. The two had once studied alchemy together, and their achievements were world-renowned.

Now that Severus had found a crucial lead, the French Ministry of Magic was unwilling to pursue it further… but Dumbledore would be different.

As a key figure involved in nearly every major event in the European wizarding world throughout the 20th century, Dumbledore undoubtedly knew far more secrets than the French Ministry.

"You stay here and look after Harry and Draco. I'll return to Hogwarts to speak with Dumbledore." Severus said to Lupin.

With Lupin around to help, Severus found certain tasks much easier to handle.

After giving Lupin some instructions, Severus didn't use the French Ministry's Floo for international travel directly. Instead, he left the Ministry and found a wizarding tavern in Paris.

From there, he used the Floo Network to travel to Calais, then performed two consecutive Apparitions, finally arriving in Hogsmeade.

After this roundabout journey, Severus reached Dumbledore's office.

"I assume you've already heard about the kidnapping and disappearance of your old friend." Severus said.

Dumbledore, who had been handling documents related to the International Confederation of Wizards, set aside his work and nodded.

"I received word from France around the same day you arrived in Paris, informing me of the incident. Later, they wrote to me privately, mentioning that you had joined their investigation?"

Without hesitation, Severus placed the photos he had taken of the apartment building on Dumbledore's desk.

"I did offer them some assistance. But just as I felt I was getting closer to the truth and about to uncover the answer, they dismissed these photos and tried to stop me from investigating further."

Dumbledore listened carefully, adjusting his glasses as he picked up the photos.

The moment he saw the building in the photos, his expression turned subtly strange.

"Could you tell me where and how you took these photos?"

Severus recounted his experiences since arriving in Paris… recognizing the Shafiq, noticing the oddities of the apartment building, thwarting the culprits' planned attack on the monastery, and finally deciding to investigate the apartment as a lead, only to be threatened by Girard and ordered to stop digging deeper.

By the time Severus finished, Dumbledore's expression had shifted from subtle to one of wry amusement.

He shook his head and said, "Your final judgment of Girard was absolutely correct. After obtaining these photos from you, she must have searched the French Ministry's highest-level classified files and found records of that Austrian prison."

Severus frowned slightly. He had already come across records related to that country in the Auror Office's archives, and it was from those fragmented files that he had learned about the highest-level secrets.

"Is it a prison like Azkaban?"

"No, it's different from Azkaban. That prison once tortured and held many innocent wizards. But now, it imprisons only one person… the very man who caused the prison to be built, its original owner."

As Dumbledore spoke, a book flew out from a nearby shelf in the office.

It glided halfway across the room before landing steadily on the desk, its pages flipping rapidly as if blown by the wind. After four or five seconds, it stopped at a page with no text, only a black-and-white illustration of a tower-like structure hidden deep in a forest.

Apart from the most prominent tower protruding from the dark gray walls, the lower buildings near the ground were nearly identical to the apartment building in Severus's photos!

Beneath the illustration was the name of the structure: [Nurmengard]!

The moment he saw the name, even without recalling memories from his past life about the Harry Potter stories, Severus, drawing solely on Snape's own memories, understood exactly what the French Ministry feared he might uncover.

"Grindelwald... The people who kidnapped Nicolas Flamel… they're the Acolytes of Grindelwald!"

Just as Severus had initially suspected, once the secret of the apartment building was uncovered, the identity of the perpetrators required little further guesswork.

"These are remnants of the old Acolytes of Grindelwald. They orchestrated the kidnapping of Nicolas Flamel, intending to force him to help them free Grindelwald from Nurmengard!"

"That apartment building was chosen by them as an experimental site! The resemblance is too strong… Nicolas Flamel was taken there and coerced into conducting their experiments!"

As Severus spoke, however, he suddenly realized something didn't add up.

'If this was indeed Grindelwald's followers plotting a prison break, why hadn't it been mentioned in the original work?'

'Or was it that, in the untold history, Dumbledore had personally intervened and resolved the matter before it escalated into a major incident?'

Dumbledore obviously couldn't see what Severus was thinking. He just shook his head and said, "This is undoubtedly the work of his former followers acting on their own. The prisoner in Nurmengard would never have known about their plan to kidnap Nicolas."

Severus wasn't deeply familiar with the lore outside the main Harry Potter storyline, as he hadd only watched the original eight films, so he didn't fully grasp Dumbledore's certainty.

"How can you be so sure?"

"Because what truly imprisons him was never a physical prison." Dumbledore said softly, "It was himself. But his followers clearly fail to understand that."

Then, Dumbledore suddenly asked, "How far do you think the kidnappers have progressed in their plan?"

Countless thoughts flashed through Severus's mind. Now that the perpetrators' true identities were revealed, seemingly unrelated coincidences suddenly fell into place.

"Since the French Ministry refuses to accept this reality, that means they must be on the verge of success."