'No, this isn't right.' Lin Sanjiu floated backward, creating a distance between herself and the girl. She scrutinized the girl in front of her from head to bottom. "Is she a human?" Lin Sanjiu was uncertain.
"What are you thinking? Have you seen my brother?" Rena stamped her feet anxiously, her accessories jangling noisily. "He went out to look for you!"
Lin Sanjiu paused momentarily; she wasn't in a hurry to reply. Instead, she spelled four words: START FROM THE BEGINNING.
'Based on Rena's temper, would she accept my question dodging?' Lin Sanjiu wondered. However, predicting someone's reaction to a situation based on their usual behavior was unreliable, as humans were too complex.
Proving that point, the Rena standing before her suddenly sighed and recounted everything from the beginning.
"You went out to investigate the noise in the corridor, right? That was hours ago! 20 minutes after you left, I sensed that something was wrong. It's just a corridor. You wouldn't need that much time... I wanted to go out to check on you, so I woke my brother up." Rena gulped, looking extremely worried. "I walked around the corridor and didn't find you. He insisted on searching for you... and hasn't returned since."
Then, the girl sighed. "When he didn't return after more than 15 minutes, I went out to look for you both a couple of times but didn't see either of you. I was worried you might think I left, so I decided to wait here alone."
Lin Sanjiu listened in a daze, and without thinking about critical details, she quickly spelled: DID YOU GO DOWNSTAIRS?
"I did. I explored down to the 14th floor, checked the ground floor lobby, and even went upstairs to the roof but found nothing." Rena collapsed into the chair in the living room, appearing dispirited. Lin Sanjiu noticed a streak of dirt on Rena's white socks, likely acquired while navigating the narrow stairways.
They might have missed each other if Rena entered the stairways 30 minutes after Lin Sanjiu left. 'No, no. One floor down isn't the 14th floor. Isn't this the 16th floor?'
Lin Sanjiu got the answer to her question very quickly. When she left the apartment with this Rena, she saw the same faded 15 on the corridor.
The brain floated in midair, a little lost as to what to do next.
'Did the numbers change? But why is the unit above the same as the one below?' Lin Sanjiu thought, her mind in a jumble. She clenched her teeth and spelled to Rena: FOLLOW ME. She flew into the stairway, leading the way. It didn't matter who was real or fake. They had to meet each other before they could figure things out.
Lin Sanjiu could hear the sounds of Rena's accessories as she followed closely. After they ran down a flight of stairs, they reached the floor below them.
Sure enough, the floor below them was the 14th floor. Lin Sanjiu stared at the red 14 for half a second, then rushed to the apartment unit at the end of the corridor. However, she found a locked, unfamiliar door covered in dust as if no one had touched it in a long time.
The brain remained in front of the door, unable to piece together what had happened. 'Where is Reno?' Lin Sanjiu thought.
"What are you doing? I have already searched the 14th floor. There's nothing here!" Rena said from behind Lin Sanjiu. Rena sounded less anxious than before, probably because Lin Sanjiu was with her. "Maybe my brother is playing a prank on us again. I hate it when he disregards our situation and jokes around like this. He doesn't take things seriously at all!"
"Huh?" Even though Mrs. Manas was a step behind Lin Sanjiu, she realized that the events were unfolding strangely. But before she could say anything else, Lin Sanjiu shouted angrily in her mind, "Don't make a sound!"
Mrs. Manas immediately kept quiet. Lin Sanjiu looked at Rena, trying to observe the girl's expression. The girl was pacing fretfully and didn't show any suspicious expression. At least she didn't look like she heard Mrs. Manas.
'But what can this prove? There are all sorts of duoluozhongs in this world.' Lin Sanjiu spelled: POCKET DIMENSION?
This was the only reason that Lin Sanjiu could think of.
"No, it can't be." Rena gave a long sigh. "A pocket dimension develops from the apocalyptic world they belong to. Have you seen conjoined tangerines, where a small tangerine is stuck to a normal-sized tangerine? A pocket dimension and its world have a similar relationship. Essentially, they are the same thing... That is to say, it can be detected.
"I've checked; this isn't a pocket dimension," the girl muttered, leaning her back against the wall and crouching on the ground. "I'm sure my brother must be acting crazy again."
Considering how the girl could efficiently explain pocket dimensions, Lin Sanjiu was slightly convinced that she was the real Rena. However, Lin Sanjiu was clearer than anyone that Reno wasn't acting crazy. Reno might be in the greatest danger ever since he arrived at Kisaragi Station.
Lin Sanjiu decided not to hide anything and rapidly spelled out: I'VE SEEN HIM. HE WAS WITH YOU.
Her last sentence was certainly confusing. Rena immediately gave Lin Sanjiu a puzzled look. Lin Sanjiu was just about to add 'another you' when they heard an angry voice coming from the far end of the corridor.
"Damn you, Rena! What are you two doing hanging out here?" A head peeked from the corridor bend—a boy with fluffy, slightly messy hair.
"I looked for you both from the top floor to the lobby many times! I'm freaking tired now! Are you guys making a fool of me?" Reno said, panting as he approached. He did look like he had just walked out of the stairway.
"How dare you? You're the one who didn't return!" Rena exclaimed.
"What are you saying? When I went back, there was no one. That was why I came out to search for you guys!"
"No way! You must have gone to the wrong place--"
"Did you get stuck in the toilet!?"
The siblings quarreled for some time until they noticed that the gray brain, which had remained silent all this time, did not follow them. It was still in the same spot.
"Lin Sanjiu, what's wrong?" Rena said. "Let's go!"
Lin Sanjiu did not move. Was that really Reno?