The First Letter: The Road Pulled by Ghosts
We'd left Everlight Academy and walked deep into the island before finally arriving at a road called Lighthouse Hill on the outskirts. True to its name, a modest lighthouse stood proudly at the hill's crest. Contrary to its nickname—the road pulled by ghosts—the scenery was peaceful. No, it was actually quite beautiful. Neatly trimmed grass and trees grew in orderly rows along both sides of the well-maintained path. A slightly briny tang mingled with the cool, refreshing breeze.
Lighthouse Hill wasn't flashy, but it captured a clean, humble slice of nature.
The moment we reached the hill, the club members turned glares on me and started demanding answers.
"So, now that we're at Lighthouse Hill, care to explain what you figured out, Teach-er?"
Elaine snapped sharply, probably because I'd teased them too much on the way here. Rone nodded vigorously, her face impatient.
"Yeah! I've been dying to know!"
But just before answering their barrage of questions, I took one last look around Lighthouse Hill to verify my initial hunch.
"Teacher!"
Rozalia called out irritably when I ignored them to scan the surroundings. The other students didn't speak up, but they were clearly reaching their limit.
Ah, can't tease them any more. Perfect timing—my check was done anyway.
As their frustration peaked, I cut them off and gave the answer.
"The solution to this ghost story is simple. This ghost story... isn't a ghost story at all."
The students froze mid-complaint.
"...Pardon? It's not a ghost story?"
I pointed at Lighthouse Hill and continued.
"The core of this Lighthouse Hill tale, right? It's an uphill road, but somehow carriages and carts go backward. And objects too."
"Yes. So we came here thinking it might be a ghost story that twists space," Elaine said, looking confused.
I grinned. "Nope. Nothing like that. It's just a simple optical illusion. What happens on this hill isn't objects rolling up against gravity from the start. People just mistake normal downhill-rolling objects for going uphill."
With that, I pulled out a water bottle and poured some out. Part of the water soaked into the dirt as expected, but another part flowed "upward," just as described in the letter.
"See! It's not an illusion! The water's really flowing uphill!"
I tried to tell you.
"In my previous life, back in Korea, there was a place called 'Goblin Road.'"
Its features? Spilled water flowing uphill, or cars in neutral rolling up the hill. Exactly like this Lighthouse Hill.
But my old world—Earth—unlike Hifnia, had no ghost stories.
...At least, as far as I knew.
...Right?
Anyway, that meant Goblin Road phenomena could be fully explained by science. And if Goblin Roads could, so could Lighthouse Hill.
"It's an optical illusion. Our brains don't just use visual input; they combine it with senses like the vestibular system for balance to perceive space. But in places like Lighthouse Hill, where the surroundings confuse the eyes, the brain sometimes makes wrong judgments based on faulty info."
I pointed around the hill as I explained.
"See those trees lining both sides of the road?"
"...Yes. We see them," Elaine replied on behalf of the group.
"How do they look like they're growing?"
"Just normally. Straight and evenly spaced along the road."
"Exactly. To our eyes, they look perfectly straight, right?"
"So they aren't?"
I gestured at the surrounding trees.
"This island with Everlight Academy always has steady, strong winds blowing from the sea. Trees growing against that wind all tilt the same way. A uniform row of subtly tilted trees tricks people into misjudging the actual slope. Our eyes gauge depth and incline through relative comparisons to the surroundings. It's efficient usually, but in unique spots like this, it backfires."
Not just Elaine—the other students' eyes widened in surprise.
"S-So you're saying this road is actually a downhill slope, not uphill? Just from tilted trees? Is that even possible?"
"For this illusion to work, you need more than just regular tree growth patterns. Lighthouse Hill luckily meets all those conditions."
"What conditions?"
"One big one: the absence or distortion of the horizon line."
I went on. "Look around Lighthouse Hill. Besides the trees, there's no clear reference for level ground—like the horizon or tall buildings. If there were a massive, objective benchmark like the horizon, even confusing trees couldn't fool us; we'd correct via the bigger reference."
Lighthouses are placed in open spots for visibility, with no obstacles. Here, the phenomenon extends inland from the coast: strong seaward winds, no visible horizon, flat terrain to expose the lighthouse. All these factors weave the illusion.
"So, to sum up: uniformly tilted trees fool our eyes, and this environment lacks any correcting references. Purely scientific," Elaine neatly recapped, having grasped it fully.
"Spot on. Perfect score."
"Whoa, you sounded like a real teacher just now."
"I am a real teacher."
With my explanation done, the club members relaxed, sighing in relief. Smiles lit their faces.
"A downhill slope all along... Hard to believe even seeing it."
"But now that you say downhill, it does feel a bit off..."
"That unease probably fueled the creepy rumors here."
"At least it's not a real ghost story."
Rozalia, Rone, Aurora, and Elaine chimed in one by one, laughing.
"Most ghost stories are just unexplained science or era-bound tales. This academy, where real ghost stories come alive? That's the weird part."
"So the first letter's solved?" Rozalia asked eagerly.
I nodded. "Yeah. Post this answer on the board verbatim. Satisfies the sender, and while it's harmless science now, unchecked rumors could birth a real ghost story. Better nip it."
"Then let's check the second letter on this roll!" Rone cheered excitedly.
The members gathered at the table again. I picked up the second of the four letters. As all eyes focused, we began reading the next request.
Far off, a female student watched the Paranormal Investigation Club read the second letter with venomous eyes. She was the one who'd sent those request letters.
Biting her nails, she stared at Allen Jest—who'd unveiled Lighthouse Hill's secret with one glance. Her neatly trimmed brown bob and glasses gave an intellectual air, but her face twisted with anxiety and rage.
"J-Just one look, and he reveals what took me days of agony to uncover...! No, he seemed to guess it before we even got here...!"
She clenched her fists until her knuckles whitened.
"Impossible! This makes Allen Jest look like a competent teacher! My plan to expose his incompetence everywhere...!"
Her scheme: Send mysteries the club couldn't solve. When they gave up or spouted wrong occult nonsense, she'd reveal the "true scientific truth" she'd uncovered, stripping Allen Jest's mask of the kind, affable teacher.
But now? Far from discrediting him, it'd boost his and the club's reputation.
"Can't let that happen. After what Allen Jest did to me...!"
Her glare sharpened. No way. Freshly enrolled and buzzing with excitement, he'd humiliated and insulted her. She couldn't tolerate students revering that man!
Composing herself with a deep breath, she forced a smile.
"No. Not yet. I sent more letters than that."
With that, she glared at the distant Paranormal Investigation Club reading her second letter.