They met in Reiko's kitchen, which was the most neutral space in the building: no transit documents visible, no additional family members in evidence, just a kitchen table and two cups of tea and a window onto a small garden that a previous resident had filled with ceramic cats in various sizes and expressions.
Kenji — transit Kenji, the one from the portal — sat on the left side of the table.
The man who lived in this timeline — who was also Kenji, who was structurally identical in almost every measurable way and divergent in every meaningful one — sat on the right.
They looked at each other.
"This is strange," the timeline-Kenji said.
"Extremely," the transit-Kenji agreed.
"You're me."
"A version. The divergence point was approximately twenty years ago, in our mid-thirties. At some point in our mid-thirties, you didn't follow the calculation to its conclusion. I did."
The timeline-Kenji looked at him with the careful, assessing look that Kenji recognized as his own assessment mode: patient and thorough and not willing to accept incomplete data. "Why? What made you keep going with the numbers when I stopped?"
Transit-Kenji thought about it honestly. "I had more reason to be afraid."
"Of?"
"Losing them. The family. I had more experience of — of what loss felt like, by that point. Enough that following a catastrophic calculation was less frightening than stopping it and being wrong."
Timeline-Kenji was quiet. He turned his tea cup slightly — one-eighth rotation, then back — a gesture that transit-Kenji recognized as his own and had not known he made until he watched someone else make it.
"What's under your Tokyo?" the timeline version asked.
Transit-Kenji told him. Not everything — not the portals and the trials, not yet — but the geological truth. The fault stress pattern. The methane hydrate destabilization in the bay sediment. The numbers that he had run seventeen times and that Dr. Saito had run from a different methodology and that had converged on the same answer from different directions, which is how you know the answer is real.
The timeline-Kenji listened. He listened with the same quality of attention that transit-Kenji brought to a difficult model: completely, without interruption, without performing either doubt or belief. Just receiving the data.
When it was finished, he sat for thirty seconds.
"Your timeline diverged from mine at the geological level as well," he said finally. "The methane hydrate destabilization you're describing — we don't have that here. The bay chemistry is different."
"I know. Reiko had it assessed."
"So the catastrophe is not in my timeline. But the system that was built to prevent it —" He looked around the kitchen, at the house, at the implication of thirty years of transit protocol running in his city. "Has been operating here for thirty years without being in any danger from the thing it was built for."
"Yes."
"Because the destination timeline — this one — was chosen for its geological stability."
"Yes."
Timeline-Kenji looked at his counterpart with the expression of a man who has been presented with an engineering decision that is simultaneously defensible and infuriating and is deciding how much of the infuriation to express. "Someone chose my city as a destination without asking my city."
"I chose your city. The other version of me. He chose it because it was the safest local option — the same geological formation, the same urban infrastructure, the lowest divergence from the origin timeline, which minimizes integration difficulty. It was the correct engineering decision."
"It was the correct engineering decision," the timeline version echoed, with the specific flatness of someone repeating a phrase in order to make clear how much the phrase is covering. "Forty-three families arrived in my city without my knowledge. Forty-three families were integrated into my administrative system —" He stopped. "You knew about this before you arrived."
"I knew about the transit protocol."
"Did you intend to tell me?"
A pause.
"I would have told you. Eventually. I was still — I'd been here for three hours. I hadn't worked out the order of urgencies."
"Forty-three families," the timeline-Kenji said again. "In my city. And now the system is being expanded, apparently. To move more. You came here with a second transit window to build. Hundreds more families, potentially."
"Yes."
"And you were going to do this —"
"I was going to do it," transit-Kenji said quietly, "because in approximately eighteen days, the earthquake is going to happen in my origin timeline. And when it does, people will die who could have been saved, and I built a system to save them, and right now I have a window to make it work better. The system runs under your city whether you sanction it or not. I cannot stop it — it's the original infrastructure, built into the geological substrate. What I can do, if you'll let me, is tell you everything about it and work with you on the expansion. Or I can try to build the expansion without you, which will be slower and worse and will almost certainly result in your geological survey detecting anomalies that you will then spend your time investigating instead of helping."
The two men looked at each other across Reiko's kitchen table.
The ceramic cats in the garden were visible through the window: a row of them, painted in various colors, facing the kitchen with their fixed, ceramic serenity.
"You're asking for my help," the timeline-Kenji said.
"Yes."
"You need my engineering expertise, my local knowledge, and my permission."
"Yes. All three."
"And if I say no?"
Transit-Kenji picked up his tea. "Then I build it slower and worse and people in my origin timeline die who shouldn't have." A pause. "I'm not using that as leverage. I'm telling you the consequence as an engineering fact. The way I've always told you things."
The timeline-Kenji looked at his counterpart for a long time. He looked at the specific shape of the man across the table — his own posture, his own tea-cup hold, his own way of sitting when he was waiting for a decision to arrive. He looked at the three-years-of-fear in the face that was his face and was not, at the specific quality of a man who has been carrying something very large for a very long time and is now, just now, beginning to put it down.
He thought about the three pages of calculation he had put away. He thought about what it had cost him to stop — the slight, permanent unease of a man who stopped a calculation before it was finished, who had been living for twenty years with an answer he'd chosen not to reach.
— ✦ —
"Show me the Sumida River site specifications," the timeline-Kenji said. It was not a yes. It was the thing that comes before yes, which is choosing to look at the problem. Transit-Kenji reached into his jacket — the backup notebook, which had been in his pocket since the Shinkansen and showed no signs of going anywhere — and opened it to the page where Dr. Saito's handwriting began. He passed it across the table. The timeline-Kenji looked at the Sumida River calculations. He looked at them for a long time. He turned one page. Two pages. His finger began, very slightly, to tap. "This transit window design," he said, not looking up. "The anchor load distribution is wrong. The Sumida River site has a secondary resonance layer you haven't accounted for — I found it in my survey data three weeks ago. If you build to this spec, the window will open but the coherence time will be forty percent shorter than your projections." He looked up. "Which at fifty families per window means twenty fewer families per transit event than you planned for." He put the notebook down on the table and picked up a pen from the mug on the counter that held pens the way all kitchen counters hold pens: accidentally, prolifically, in a range of states of operation. "Move over," he said. Transit-Kenji moved over. The timeline-Kenji sat beside him at the table and opened the notebook to the relevant page and began to correct the calculations. They worked, both of them, in the specific concentrated silence of engineers who have found a problem that is more interesting than the complicated feelings they were having a moment ago — which was a silence Kenji knew very well and which had, it seemed, survived intact across the divergence of twenty years and two separate lives. Above them, Reiko appeared in the doorway, looked at the two Kenjis working at the kitchen table, and went back into the hallway to make another pot of tea. In the garden, the ceramic cats watched and said nothing.