Hideo Mori was thirteen years old.
His father had died six weeks ago: a sudden cardiac event, unexpected, the kind that comes without warning and leaves behind not only grief but an apartment full of a dead man's work that no one has the context to interpret.
The work, in this case, was a stack of notebooks — fourteen of them, the same plain black kind you found at any stationery shop — and a receiver that his father had built from components Hideo didn't recognize, tuned to frequencies that didn't appear in any spectrum guide he'd been able to find, and a series of calculations in the notebooks that converged on a conclusion Hideo had been staring at for six weeks without being able to accept.
His father had been a marine chemist. He had specialized in deep sediment chemistry — the kind of research that was very specific and very technical and of interest to approximately six hundred people worldwide and none of them in Hideo's school. He had been quiet about his work in the way that people are quiet about things they believe deeply and have been unable to get anyone to care about: not secretive, exactly, but resigned. He had filed his findings in the appropriate journals. He had attended conferences where people had nodded and moved on. He had come home and continued his calculations.
The calculations said: the methane hydrate destabilization in Tokyo Bay was approximately twice as severe as the last published assessment. The reason was a feedback loop that the published assessment had not modeled: a warming effect in the deep sediment layer that was accelerating the hydrate breakdown, which was in turn releasing methane that further warmed the layer. A self-reinforcing cycle, running quietly under the bay, in the deep chemistry of the seabed.
And in the margin of the last notebook, in the tired handwriting of someone who had been working on a problem for a long time and had run out of ways to get anyone to care about it, his father had written: FIND TANAKA. HE HAS THE OTHER HALF.
Six weeks of trying to find Tanaka. Six weeks of searching every public record and professional directory and geological survey database for a Tanaka who was working on anything related to seismic prediction in Tokyo. Six weeks of finding exactly one Tanaka, a structural engineer, who had published three papers a decade ago and then gone quiet — who had no current institutional affiliation, no recent publications, no traceable professional activity.
And then, going through the receiver his father had built, tuning through the frequencies his father had been monitoring: the 31.7 band. And on the 31.7 band, a signal unlike anything Hideo had ever heard from a receiver — something structured, purposeful, clearly not atmospheric noise or transit bleed, clearly carrying information.
He had been transmitting on the secondary band for three days before Tomoko Abe answered.
He told her all of this — sitting at his father's desk, holding the last notebook, speaking into the transmitter his father had built — in the careful, too-formal language of someone who is very young and very afraid and has decided that the way to be taken seriously is to be precise.
On the other end of the frequency, Tomoko Abe listened with the attention she gave everything: completely, without performing either doubt or certainty, building her model from the incoming data.
When he finished, she said: "FIND TANAKA. How long ago did your father write that?"
"The date on the page is five months ago."
"Five months ago he was looking for a structural engineer in Tokyo named Tanaka."
"Yes."
"I've met the Tanaka he was looking for." A pause on the line. "Can you bring the notebooks?"
"To where?"
"I'll send you an address."
Hideo Mori arrived at Reiko's house two days later, having crossed the city by train with fourteen notebooks in a backpack that was too heavy and a face that was doing its best to perform the calm of someone on a routine errand. He was small for thirteen — the kind of small that looked younger and thought older — and he stood on the doorstep with the backpack and the formal, careful posture of someone who has rehearsed what they're going to say.
Tomoko met him at the door. She was, he noted, also young — slightly older than him, slightly smaller, with a directness that he found immediately more manageable than the adult careful-kindness he'd been receiving since his father died.
"You're Mori Hideo," she said.
"Yes."
"I read the secondary band transcripts of your transmissions. You're careful."
"My father taught me to be careful with frequencies. He said they carried exactly what you put into them and nothing you didn't."
Tomoko looked at him for a moment. "Come in," she said. "There are people who need to see these notebooks."
The meeting happened around Reiko's kitchen table: transit-Kenji, timeline-Kenji, Dr. Saito's notes (relayed through the system by the new anchor connection), and Hideo Mori's fourteen notebooks.
The methane hydrate data was worse than Dr. Saito had projected.
The two engineers sat with the notebooks for two hours. Hideo sat at the table's edge and watched them work — watched the two versions of the same man converge on the same conclusions from different starting points, watched the understanding of the numbers land in their faces in the same way at the same speed, which was eerie and fascinating in equal measure.
"The secondary event," transit-Kenji said, at the end of the two hours. He said it quietly, to the table, to the numbers.
"Your margin is wrong," timeline-Kenji said. "Your model had the secondary at 7.9 to 8.1. Mori's data puts it at 8.4 to 8.6."
"Which means the projected casualty figures —"
"Double, approximately, for the secondary event."
Transit-Kenji closed his eyes for three seconds. "The timeline for the bridge window. We said eleven days for installation."
"Yes."
"Can it be eight?"
Timeline-Kenji looked at his counterpart. He looked at the notebooks. He made the calculation that Kenji always made before stating a timeline: not the ideal scenario timeline but the worst-case scenario timeline. What could go wrong, how long it would take if things went wrong, what the actual margin was.
"Eight days is possible," he said finally. "If I work continuously. If the bridge access schedule holds. If the resonance emitter components arrive on schedule — I placed the order this morning."
"If," transit-Kenji said.
"Engineering is always if. The question is how many ifs and how controllable they are."
Hideo, at the table's edge, had been very quiet during all of this. He spoke now, with the precision he'd inherited from his father: "My father found the methane hydrate feedback loop six months ago. He tried to publish. He tried to report it to three separate bodies. He was told his methodology was non-standard." A pause. "He died with nobody believing him. I need to know that his work is —" He stopped. Started again. "I need to know it mattered."
— ✦ —
Transit-Kenji looked at this boy across the table — thirteen years old, his father dead six weeks, sitting with fourteen notebooks and a receiver and the specific weight of a grief that has not yet found its shape — and thought of himself, three years ago, at his desk in his study, running calculations that he could not get anyone to believe. He thought of the middle shelf. He thought of the empty space where the notebook had been. He said: "Your father's work identified a variable that changed my projections. Without his data, the Sumida River window would have been calibrated for the wrong event magnitude. It would have moved people to safety before the primary event and had no capacity for the secondary." He paused. "Because of your father's notebooks, we are redesigning the capacity matrix to account for the secondary. People who would have been in transit during the secondary event without a window open — they will have a window open." He looked at Hideo. "His work mattered. And so does yours, because you came here." Hideo looked at the table. He looked at the fourteen notebooks. He looked up. Something in his face had settled, or was beginning to — the specific shift of someone who has received an answer they needed and is discovering that the answer, while good, is not the same as the grief resolving. It helps. It does not fix. He said: "Can I help? With the window. With what you're building." Tomoko, beside him, looked at transit-Kenji. Transit-Kenji looked at timeline-Kenji. Timeline-Kenji, who had been working alone on a calculation for three weeks and had been working collaboratively for four days and had found collaboration significantly more effective, said: "Yes. The methane hydrate feedback data — we need it integrated into the transit capacity model. It's chemistry, not engineering. We need someone who can translate." Hideo sat up straighter. He opened the nearest notebook. He said: "Page seven. This is where it starts."