Ten minutes earlier.
"Wait for me!"
Hermione panted as she chased after Nana, watching the black creature ahead become barely visible in the swirling mist. She finally couldn't help calling out desperately.
Hearing Hermione's shout, Nana slowed down slightly, then looked back at her with a distinctly human expression of disdain.
As if to say: how could this little girl have such poor stamina?
Still, after slowing her pace, Hermione could finally keep up with the determined Niffler.
Following behind Nana, Hermione tried to piece together what had happened so far.
She and Nana had initially appeared in what looked like Hogwarts' Great Hall. Shortly after materialising, Nana had suddenly stopped and begun sniffing the air frantically, then wriggled free from Hermione's embrace and taken off running in one particular direction.
It looked like she'd caught the scent of some incredible treasure.
Since Professor Kahn had earnestly recommended Nana to her last night, saying the creature would play an important role in this assessment, Hermione didn't doubt her instincts and followed directly.
But the further they went, the more she felt something was wrong with their surroundings.
The air around them was gradually becoming cold and gloomy, with a distinct chill creeping up her spine. Shadows seemed to press in from all sides.
They were now running down a stone staircase, and Hermione recognised it as the path leading to the dungeons where the Slytherin common room was located. Could Professor Kahn have set up puzzles in the dungeons? That was certainly possible, but she had rarely been to Hogwarts' lower levels. Aside from the Potions classroom, she wasn't familiar with any of the buildings down here.
Unfamiliar places always made her somewhat anxious.
Following the staircase down, they soon reached the bottom, where a stone serpent stretched along the wall, exactly as she remembered.
She'd heard from older students that if Slytherin students approached the serpent, it would rise at an angle to let them pass into their common room.
However, she wasn't a Slytherin student, so she had no right to enter.
The surroundings formed a narrow corridor where the mist seemed slightly thinner than above, not nearly as dense as the upper floors.
"Are the puzzles here... huh? Where are you going?"
Hands on her knees, just about to catch her breath, Hermione suddenly discovered that Nana showed no signs of stopping and continued rushing deeper into the castle's depths.
Gritting her teeth, Hermione once again chased after that determined black figure, running toward the deepest parts of the dungeons.
As they went deeper, the cold dungeon air completely enveloped her. However, this level didn't seem to have the legendary bones or terrifying decorations she'd heard about. It didn't look that scary at all.
Moreover, she'd seen many strange specimens and preserved creatures in jars during Potions class, but none of those things were here. Just empty stone corridors and vacant chambers.
Maybe this is actually just a replica similar to Hogwarts?
She'd actually suspected this when they first arrived at the Great Hall. After all, Professor Kahn couldn't possibly evacuate all the students and professors from the real castle just for one assessment.
But if it was just a replica, where had the professor gotten a castle identical to Hogwarts in every detail?
With these questions swirling in her mind, Hermione continued following Nana deeper into the dungeon complex.
Passing through archway after archway, the light ahead became increasingly dim. If not for the faintly glowing white mist providing illumination, Hermione strongly suspected there would be no light here at all.
Keeping close to Nana's determined pace, another downward staircase appeared ahead. That led to the second underground level's old water prison, also Hogwarts' lowest accessible level.
She'd never been there and didn't know what to expect. Many older students had mentioned it was once a place for imprisoning students who made serious mistakes, filled with countless instruments of punishment. But since this was a replica of Hogwarts, there shouldn't be those terrifying things, right?
Following the staircase down, she found herself in a very low, stone-vaulted chamber. Just as she'd hoped, there was no standing water here, nor any torture devices or wandering spirits.
And on this level, Nana's pace finally began to slow.
The Niffler sniffed left and right, ran forward about twenty metres, then stopped in place, squeaking excitedly and pointing at the floor tiles below with one tiny paw.
Panting as she ran to Nana's side, Hermione first took several deep breaths. After catching her breath, she tilted her head somewhat suspiciously and asked softly:
"Are you sure it's down there?"
She hadn't seen any hints related to puzzles anywhere nearby. If the professor had hidden his assessment challenge under the second-level dungeon's floor tiles, this puzzle was buried far too secretly, wasn't it?
Who could possibly discover it without a treasure-hunting Niffler?
However, seeing Nana's absolutely determined expression, Hermione still nodded and drew her wand with resignation.
"Alright then. Defodio!"
The wand emitted a bright orange-yellow light. The smooth floor tiles cracked and flew apart, revealing a hole about three metres deep in the stone floor.
Below the hole, the stone bricks that had originally constructed the castle foundation had disappeared, replaced by ordinary rock and soil. This seemed to extend beyond the castle's boundaries entirely.
But a three-metre-deep hole on the first try?
Hermione's expression grew confused. Her Gouging Charm could usually only excavate about half a metre of solid material. Why was today's spell so remarkably effective?
However, seeing Nana continuing to point downward with increasing excitement, Hermione felt something still wasn't quite right.
"We still need to go deeper?"
Three metres underground and still no puzzle had appeared. Just how deep had Professor Kahn buried this challenge?
But Nana's expression remained absolutely resolute. The little creature seemed completely certain there was some amazing discovery waiting below.
Thinking of what Professor Kahn had emphasised last night about Nana playing a very important role in this assessment, Hermione no longer hesitated and continued casting the spell at the earth below.
But after continuously casting six Gouging Charms, she felt somewhat overwhelmed.
The mist in the castle was already constantly weakening her mental state, and the Gouging Charm was advanced third-year magic. Using it six times consecutively was putting a serious strain on her magical reserves.
"Still... still need to go deeper?"
Holding her somewhat aching head and staring down at the impressively large hole she'd excavated, Hermione felt completely baffled.
Would Professor Kahn really hide puzzles so deep underground that only a Niffler could find them?
At such depth, without Nana's guidance, she definitely wouldn't have attempted digging here. Even after excavating so much earth, she hadn't seen a trace of any puzzle or magical signature.
However, today's Gouging Charm did feel unusually effective. She estimated she'd already dug at least twenty metres deep. Normally, after excavating about three metres, the spell would become too difficult to maintain.
Maybe the soil here has been specially enchanted by Professor Kahn to be easily excavated by the Gouging Charm?
Eyes brightening as she thought she'd identified the key mechanism, Hermione renewed her determination and drew her wand, aiming it downward once more.
After three more carefully aimed Gouging Charms, accompanied by the sound of flying dust and scattered pebbles, Hermione finally saw something completely different appear far below.
It looked like a massive stone panel, but most of it remained buried by the surrounding soil. Only this small section she'd painstakingly excavated glimmered faintly with ancient magical light, seemingly bearing some kind of very old, very powerful seal.