Her name was Tomoko Abe.
She was fourteen years old. She lived in the Koto Ward. Her family had been in the Koto Ward for four generations, which meant her family had deep roots in exactly the neighborhood that Kenji's models had projected as being most heavily impacted by the primary seismic event.
She explained all of this standing in the doorway of the trial station — the steel door still open behind her, the sounds of Tokyo still audible from the other side — with the brisk, matter-of-fact delivery of someone who has rehearsed what they would say if they ever found the person they were looking for.
"I found the frequency eight months ago," Tomoko said. "My mother's a radio engineer — old-school, the analog kind. She has a receiver set up in the apartment that can pick up non-standard frequencies, for her work. I was using it one night and I found yours."
"You've been listening to the frequency for eight months," Kenji said.
"I couldn't understand most of it. But I understood the seismic data you were broadcasting, because my mother had taught me how to read it. And I understood the words 'portal' and 'transit.' And then I found the trail — you'd been active at this mountain-tunnel location several times in the past year, running calibrations. I figured if the frequency was strongest there, and there was something about a transit —" She shrugged with the pragmatic economy of a teenager who has done something remarkable and decided the most efficient way to handle it is to treat it as unremarkable. "I got on the train."
"You followed my frequency onto the Shinkansen," Kenji said, "without telling anyone."
"I told my best friend. She thinks I'm eccentric. That's a useful reputation to have."
Dr. Saito, who had been listening with the expression of someone encountering a phenomenon they weren't sure whether to be alarmed by or impressed by and had landed on both simultaneously, said: "How did you get through the door?"
"The door was open. I just walked through."
"The door was —" Dr. Saito looked at Kenji. "That should not be possible. The trial boundary —"
"The trial boundary was already compromised by my door opening unscheduled," Kenji said. "My portal misfired, created a secondary access point. And the system acceleration may have degraded the boundary further." He looked at Tomoko. "You said your whole neighborhood. You came here for your whole neighborhood."
Tomoko met his look with the direct, slightly-too-old-for-her-age gaze that the previous months had apparently constructed in her. "You have a portal system. I have a neighborhood full of people who don't know what's coming. Those are two problems that seem related."
Kenji thought about the screen: eleven families currently in trial. He thought about Dr. Saito's revised projections. He thought about an anchor already under strain, a system designed for one family now running eleven, and a geologist willing to become the second anchor because she had no family waiting and she had found a purpose in the gap between her skills and the disaster.
He thought about a fourteen-year-old girl who had found a radio frequency and followed it onto a train and walked through an open door in the fabric of reality to ask for help for her neighborhood.
He thought: this is the kind of person the world is made of. Not the ones who accept the limits of what's possible. The ones who walk through the door that was accidentally left open.
"What's your background?" Dr. Saito asked Tomoko. Practical, direct, the question of someone assessing an asset.
"I'm fourteen."
"What do you know how to do?"
Tomoko thought for a moment. "I can read seismic data, analog radio transmission, basic network topology. I know every street in Koto Ward to within two blocks. I know which buildings were built in which decade and which ones have the earthquake resistance upgrades because my mother made me check when we moved in. I can write clear lists that people will actually follow in an emergency." She paused. "Also I'm good at finding people who don't want to be found."
Dr. Saito looked at Kenji.
"She can inventory the neighborhood's structural risk and create an evacuation priority list," Dr. Saito said. "For when we expand the system."
"For when we expand," Kenji said. The word we settling into his usage without his having decided to use it, which was how we usually arrived.
Tomoko looked between them. "You're going to expand the system."
"The system needs a second anchor," Kenji said. He nodded at Dr. Saito. She nodded back, without flinching, which told him more about her than an hour of conversation had. "Dr. Saito has agreed to take it. If we can build the capacity before the timeline accelerates further, we can expand the number of families the system can move."
"How many families?" Tomoko asked.
Dr. Saito was already doing the calculation, her pen moving in the red notebook. "Conservatively? With two anchors and a rebuilt capacity matrix — fifty families per transit window. Possibly more if the resonance conditions hold."
Tomoko did her own math. Koto Ward: 490,000 residents. Average family size in the ward: 3.2 members. Families at highest structural risk, based on the building data she'd memorized: roughly eight thousand.
"We need more transit windows," she said.
"The window is determined by the seismic resonance. We don't control the window."
"Can we make a second window?"
Kenji and Dr. Saito looked at each other.
"The frequency the tunnel uses," Dr. Saito said slowly. "It's specific to that geological location. But if there's another location with comparable resonance —"
"The Sumida River bridge," Kenji said. He was already moving toward the departure boards, looking at his city on the screens. "The deep strata under the riverbed have a similar resonance signature — I dismissed it originally because the frequency differential was too high to use with my original design. But if the anchor design is different —"
"A different anchor design," Dr. Saito said, "might work on a different frequency."
They both looked at Tomoko, who had been following this exchange with the quick, connecting attention of someone who has found the room where the interesting things are happening and is determined to stay in it.
"What?" she said.
"The Sumida River bridge," Kenji said. "Do you know it?"
"I live two kilometers from it."
"Would you be able to find it in your city, in the time between now and when this trial ends, and mark the activation coordinates?"
Tomoko looked at the open steel door, at the city noise coming through it, at everything waiting on the other side.
"Yes," she said. "But I need something first."
— ✦ —
"I need to know," Tomoko said, very precisely, with the flat clarity of someone asking a question they have been saving for the right moment and who will not be answered with anything less than the truth, "what happens to the people who don't make it through. Not the ones who refuse or don't know. The ones who find the frequency, who find the door, who are trying — and the system fails them. What happens to them?" The station was very quiet. The departure boards showed Tokyo in the afternoon light, ordinary and unknowing. Dr. Saito looked at Kenji. Kenji looked at the boards. He thought about the screen on the Shinkansen: ONE HAS BEEN IN TRIAL FOR TWO YEARS. He thought about Yuki, three years in Polaris City. He thought about Mei in a time-distorted forest zone. He thought about the other Aiko on the bridge, and Sora in the trees, and all the people in all the environments who had not completed their trials and had become, in their various ways, part of the system's infrastructure. He thought: this is my trial. This is the honest thing I have not been able to say. He turned to Tomoko and said it. "Some of them become part of the system. The environments need management, they need memory, they need anchoring. The people who stay — who can't leave or won't leave — they become that. They don't disappear. They don't suffer. But they also don't go home." Tomoko absorbed this. "And you built this system." "Yes." "Knowing that some people would get stuck." "I —" He stopped. "No. I didn't know that part. But I should have looked harder for it. And I didn't." The steel door behind Tomoko began, very slowly, to close. The sounds of the city started to dim. "The door is closing," Tomoko said. "I have to decide." She looked at Kenji. "Are you going to fix it? The part where people get stuck?" He looked at her — this fourteen-year-old girl with her mother's radio receiver and her neighborhood and her clear, demanding question — and said the only honest thing: "I am going to spend the rest of my life trying."