Considering that this Wooden House was in the middle of nowhere, and that there were no survival supplies once they left it, if the diary's owner had truly been held up by something, it could not have been far from the house. Schiller suspected there was something wrong with the house itself.
As for what exactly was wrong, Schiller had some guesses, mainly because the number of fish dug out of the man's stomach was abnormal.
The monster had come to kill people, not compete in a fishing tournament. Assuming it possessed intelligence, it would only fulfill a corpse's wish to the minimum extent necessary to kill it more effectively.
Whether fishing with nets or rods, it was a time-consuming task. If this man's wish had been to go fishing and eat the fish himself, wouldn't one fish have been enough? Two or three fish that large would have been enough to stuff him to death.
Yet Schiller had found around a dozen fish in the man's stomach, and they all looked similarly fresh. Was this monster really kind enough to exceed its assignment?
So Schiller thought those fish might not have been caught by the monster at all. Perhaps the man had caught them while waiting for his friend to arrive.
That was understandable. A friend was coming over, so how could he not prepare a meal? To cook, he needed ingredients. Most of what he bought from town might not have been very fresh, and since he enjoyed fishing, it was perfectly normal for him to choose fish as the main course.
If that was the case, the man's wish might simply have been to eat fish. The monster might not have understood the act of eating very well. As long as it filled his stomach, that was