First, during his initial exploration, Shiller discovered the conditions of the people in rooms 1901 and 1903, and on the first night, he heard the sound of the elevator.
Immediately after, the person in room 1903 introduced a rule, which was that the alarm in the room must be triggered to ensure one's safety.
Then, Jerome on Peter's end explained the rule, stating that the bell sound was a detection device; it would only ring if the person in the room was not contaminated.
Furthermore, by reasoning that the bell rang in their own room indicated they were not contaminated, one would then consider that the bell rang five times on the 19th floor, implying there were five living people throughout the floor.
In fact, there was a very obvious flaw in the entire investigation, which was that all these rules were spoken through human mouths.
People might doubt when one person spoke; they might choose to believe part of the story when two people spoke; when three people spoke, people would corroborate with each other, and the credibility would drastically increase when everyone was saying the same thing.
And if these three people had different identities, states of being, or even possibly existed in different spatiotemporal dimensions, their corroborating testimonies would inevitably lead people to believe them.
One person prepares the hook, another attaches the bait, and yet another casts the line; Shiller was too familiar with this fishing process.
And the short man, Jerome, and Gordon were likely playing these three roles.
Upon careful consideration, the short man in room 1903 was an obvious anomaly, as he did not even have legs but merely a voice attached to the door. It was clear to anyone that there was something amiss, so they might not fully trust what he said.
But Jerome was much harder to discern, staying in another hotel, invisible to Shiller, and acting very much like a normal person, which was the most abnormal thing, given that in Peter's hotel everyone appeared normal, implying that the equally normal-looking Jerome could be just as frightening as them.
As for Gordon, the situation was almost indistinguishable from reality, since as soon as there was one less bell sound in the right corridor, people would have difficulty determining whether room 1901 or room 1903 was problematic, so they would unavoidably steer their thoughts towards the possibility of two living people in the left corridor.
Once convinced there were two living people in the left corridor and having rescued Gordon in room 1907, they would definitely believe Gordon was one of the living, because he was saved by them. People are naturally inclined to trust their own efforts more.
The short man brought up the bell sound, Jerome explained it, and Gordon supplemented with the rule that uninfected people would not kill, making the chain of clues very comprehensive.
All these rules pointed to one path—if one could confirm they were not contaminated, then they would surely be able to use the detection device to take the elevator and leave the 19th floor.
But from beginning to end, this rule about the bell had no evidence; it was just one person after another speaking, and the only alarm clock that existed in the room had never truly been seen ringing by Shiller.
This took great advantage of human psychology's weak points. First is the concept that a lie repeated often enough becomes the truth; the more people who say it, the more credible it becomes.
Secondly, if both the good and evil sides emphasize the same point, people will tend to believe one of them, thinking that at least one perspective must be correct, rather than assuming both could be wrong. This was the principle that the "barbed hook" relied upon.
It was precisely Gordon who made Shiller realize this was a trap.
Before asking what happened to Gordon, one must first ask, why Gordon?
His presence here was the biggest question—Gotham had so many lunatics and villains; why was it specifically this police commissioner?
Bruce knew Gordon, and so did Shiller; there wouldn't be a shortage of people in the city who knew this commissioner. Gordon was that remarkable, being the last beacon of light in a dark city, and countless people trusted and followed him.
Even if others didn't know he was Gordon, upon seeing his police uniform, they would be more inclined to believe what he said. After all, in this terrifying Gotham, anyone willing to don the uniform, even if it were for bribe money, is a hero—a truth most people understand.
So, relying on their wits, people exhausted physical and mental effort to find such a commissioner, like grasping a lifeline in the vast ocean. There was no reason not to believe and rely on him.
The prolonged feelings of fear, loneliness, and lack of response can render people truly vulnerable as babies, crying out desperately in a last-ditch attempt to garner their mother's attention.
And in the moment the mother responds, they have no reason to consider whether the one picking them up is a mother or a monster, as long as she offers comfort; for ordinary people, this is an inescapable trap.
Gordon provided the most deadly rule, a continuation of the earlier setup but even more intricate, namely that the entity patrolling the hallway would not harm those uninfected.
Though he outright said it was a bet, every single clue indicated that as long as you wagered, you would win for certain, since you met all the conditions for winning—no gambler could refuse that.
Of course, this sounded too much like the unfounded suspicions of someone with paranoid delusions, after all Shiller's own conjectures lacked evidence as well.
Just as he thought this, Shiller suddenly remembered that he did have evidence, albeit not entirely reliable, but far more substantial than what those people provided.
It still has to be traced back to room 1905.
As mentioned before, the tactics the room employed during the outbreak did not seem at all aimed at taking Shiller's life; it might be bound by certain rules and unable to kill directly, a viewpoint Shiller still maintained.
But this did not mean the room didn't want to kill. Since it couldn't act on its own, it would definitely try to coerce suicide.
There appeared to have been two paths to suicide; Shiller had previously guessed the room wanted to force him into the bathroom, which now seemed likely due to the possibility of contaminated water there.
The other path was, of course, jumping out the window, an unquestionably fatal choice.
But there was a third hidden path, one Shiller had also considered but hadn't taken—rushing out of the room door to the corridor as swiftly as possible.
Yet this was the most obvious escape a normal person might take; who doesn't think of running out the door when furniture starts flying at them?
If Shiller wasn't mistaken, the room wouldn't let anyone escape so easily; it would wait until midnight, intending for anyone who dashed out to confront the entity in the hallway head-on.
The room wanted to kill, so the fact that it laid out such an obvious path indicated that encountering the mysterious entity was synonymous with suicide.