Considering the isolation of the cabin—no village ahead and no store behind—and the lack of survival supplies after leaving the house, if the owner of the diary was indeed restricted by something, it was likely not far from around the house, hence Shiller suspected there might be something wrong with the house.
As for what the problem might be, Shiller had some guesses, mainly because of the abnormal number of fish he found in the man's belly.
Monsters are here to kill people, not to participate in fishing contests. Assuming the monster has intelligence, to kill more effectively, it would only fulfill the body's desires at the minimum required.
Whether it's catching fish by hand or angling, both are time-consuming tasks. Assuming this man's wish was to go fishing and then eat by himself, wouldn't one fish be enough? A couple of big ones would definitely be too much for him.
But Shiller found about a dozen fish in the man's stomach, all appearing to be quite fresh. Was the monster unusually generous and over-fulfilled the task?
Therefore, Shiller thought these fish might not be dropped by the monster but were caught by the man while awaiting his friend.
That would be understandable. After all, how could he not prepare a meal with a friend coming over? For cooking, ingredients are essential; those bought from the town may not be very fresh, plus his passion for fishing would naturally lead him to choose fish as the main dish.
If that's the case, the man's wish might be simply to eat fish, and the monster might not understand the act of eating well, just stuffing the belly to fulfill the duty, thus swallowing so many fish at once.
However, the diary states that no fish could be caught in recent days. When the monster arrived, there were so many fish in the kitchen. Where did this man get these fish?
The doubts surrounding the corpse in the kitchen were too numerous to ignore, but no matter what secrets he had, they might be glimpsed from somewhere in the room.
Shiller, however, did not trust his luck.
If he were to investigate clues bit by bit inside the house, he would most likely end up in a dire situation.
Relying on luck for clues was a gamble, and burning down the house to preserve evidence was also a gamble. Shiller preferred a more satisfying approach.
Fortunately, his luck wasn't too bad, as the clues were in the structure of the house itself. Had he not burned down the house, who knows how long it would have taken to discover a cellar beneath it.
Shiller and Batman both glanced downwards; the cellar wasn't very deep, and one wouldn't be hurt by jumping down, but it was very dark inside, and nobody knew what was there.
"I have a flashlight here," said Night Owl, "but I don't think throwing it down is a good idea."
"I'll go," Greed replied, "My camera has a night vision mode, so I can see clearly what's inside. I'm agile enough to climb back up quickly in case of danger."
Shiller did not object. Greed got closer to the hole, holding the camera in one hand and supporting himself on the edge with the other; he first sat on the edge then jumped down.
"... God!"
"What happened?" Shiller asked.
"It's shockingly large down here," Greed's voice came through, appearing to have stayed near the hole and not moved far, but seemed to have seen something surprising.
Night Owl immediately turned on the flashlight and jumped down, emitting the same exclamation as Greed.
Shiller didn't understand what could be so astonishing about a cellar until he jumped down himself, only to discover that this was not just a cellar; it was a natural underground cavern.
Jumping down, the light from the flashlight revealed that near the cellar mouth, there were some wooden floors and boxes stored, along with oil lamps, but the lamps were out of oil.
Further inside was a purely natural formation, evident from the rock structure—it was a natural cave, not a man-made excavation.
Shiller just landed and heard something; he said, "Keep quiet for a moment."
Everyone silenced, and Shiller listened carefully then said, "There's the sound of water, right ahead."
"Should we really go over there?" The Pale Knight visibly hesitated.
"If I'm not mistaken, we might have arrived someplace we shouldn't have ahead of time," Shiller hinted vaguely.
What he meant was they might have skipped steps.
Ideally, they should have gone to the village for clues, then found hints related to the diary owner in the village, suggesting some secrets of his.
After all, the diary explicitly states how unsightly and disliked he was, but the village still turned to him in times of trouble—evidence that someone in the village must know the story of the diary's owner.
They might have gone to the village to inquire about these stories, hear about a detective's activities, then returned to this cabin to carefully search it, finally discovering the cellar.
But Shiller's unconventional approach to gathering clues led them to discover the cellar prematurely.
But this was also a good thing. After all, they had no survival supplies after burning down the house, and in such deep snow and low temperatures, it wasn't realistic to walk such a long distance. Having a new exploration route was better.
Shiller inwardly wondered if this was truly what being a Transcendent entailed. The Transcendent didn't answer, but Shiller faintly heard the sound of his defense breaking.
Shiller could completely understand, since the village might just be a meticulously modeled map, likely filled with various temperamental NPCs, and his group had completely skipped a significant section.
"Let's go," Shiller said. "There's nowhere else to go now, it would be great if this cave led inside the village."
Listening to his meaning-laden words, Universe Batman looked back at him, slightly lagged behind, and came up beside Shiller, asking, "Where do you think this cave might lead?"
"I guess it's probably a secret location, there might be monsters we can't handle, but there could also be tempting clues."
This statement seemed to say nothing at all, but to Universe Batman, it was probably "You better not set us up with monsters we can't handle and leave some enticing clues behind, or I won't follow the script."
Bruce, who was up ahead, was whispering with Greed, while Night Owl, leading and illuminating the path, kept looking back intensely, to the point that Shiller thought he could kill insects with his furrowed brows.
The sound of water grew louder.
After turning a narrow corner, a vast cavernous space opened up before them, with an underground river at its center, the source of the water sounds.
Shiller didn't get too close to the water, but he could see the numerous fish constantly jumping out from the dark river, so many that one could easily net a full catch.
Night Owl shone his flashlight towards the river, allowing Shiller to see more clearly that the fish in the underground river were identical to those found in the belly of the corpse in the kitchen.
That meant, although no fish could be caught above ground, they were still catchable underground.
The owner of the diary had major issues indeed. Bruce looked at the river and said, "To have such a large hole under one's house, containing an underground river, and fishing from it—do the villagers know about this?"
He neither farmed nor herded, yet he mentioned in the diary about going to the village to buy food; where did his money come from, Greed sharply captured the essence, asking, "His only apparent means of making money seems to be fishing, and if he can't fish above ground, he would fish underground. But are the fish underground really edible?"
The truth might just be the opposite. Shiller too stared at the fish continually thrashing in the dark waters, commenting, "Not only are the fish underground edible, but they might also have some special effects, otherwise why would people from the village come to him? And why would his kitchen suddenly have so many fish?"
Others quickly grasped this point as well.
Without hot water, the freshness of the fish would rapidly decline, and ordinary people seldom stored large quantities of fish.
Just he and his detective friend eating would not require dozens of fish, and if the fish really were caught by the diary owner himself, this indicated not just they, but others, might have placed orders for these fish.
Considering the cottage's location, other than villagers, there likely wasn't anyone else to buy so much fish.
With terrifying monsters appearing in the village, yet the villagers still indulging in lavish meals, if their sanity was not in question, then these fish must play a role in dealing with the monsters.
Realizing this, Shiller had an epiphany, "The monster intentionally made that corpse swallow all the fish so others couldn't eat them."
Universe Batman also understood; the diary owner's last wish might not have been to eat the fish, but the monster could control him to consume all the fish, so even if some villagers found this place, the fish would be completely rotted, inedible.
"Should we catch one to try?" Bruce was already rolling up his sleeves.
Fishing was actually simple; not to mention they were all wearing coats, the sheer number of fish made it seem like merely reaching in could yield a catch.
Shiller also wanted to bring one up to check, but considering safety, he thought it better not to get too close to the water's edge.
Greed was obviously more aggressive, directly suggesting to Universe Batman, "I think you can shoot into the lake."
"This is a shotgun, not a crossbow arrow, the bullet can't bring the fish back," Universe Batman replied.
"It's not about the fish, but if there's something dangerous in the lake, you might be able to provoke it."
"What a madman," Night Owl muttered after glancing at Greed and pulled Bruce a little closer.
"Aren't you going to take a picture of them?" Shiller suddenly said.
"What are you shooting? A fish memorial?" Greed joked. Before Shiller could say more, Greed walked over to him and put an arm around his shoulder.
Universe Batman edged a bit closer to the riverbank, noticing how the fish's scales under the faint light reflected twinkling silver gleams, creating an eerie vitality that didn't fit the dark, enclosed cave.
He looked towards where the river flowed from, seeing nothing but darkness, and the downstream was the same.
"I think we should follow the riverbank." Even though Universe Batman saw another path on the opposite side of the river, he still suggested this.
"Okay, let's go with your idea," Greed appeared to temporarily abandon some risky plans, and no one else objected.
Shiller looked down at his fingers; when he had picked up that charred plank, black ash had rubbed onto his fingertips, but oddly, he hadn't used a beast skin to clean his hands.