You can tell because she's the one with the toolkit on her suit. "You've come to the right Lorica, yeah."

Oh thank god.

"I was wondering if you can do mass transportation projects. They're going to set-up a second portal here to the same earth as the one back home and it'd be really neat if we could take advantage of the empty earth to set-up high speed transit between the two." 

"I could give Rete a train, probably, if that'd do."

"Do you mean give her an existing train or build her a new one?"

"Rete's an it. It'd certainly be faster to get train cars from somewhere that mass-produces them, and maybe most of the locomotives too."

"What sort of advantages might it manage over traditional set-ups?

"Well, you wouldn't have to staff it, and you could wiggle the capacity around in response to demand more fluidly, but honestly trains are trains, I'm not sure it'd be all that great an improvement."

"Hrm, could you manage automated maintenance?"

"Of non-tinker trains, sure."

"Would the repair tech itself require maintenance by you? Tinker tech infrastructure projects usually aren't feasible because they are dependent on their tinkers being around for a while - but I remember you can automate your own maintenance work and I think most of it kept functioning fine when you were... gone. "

"So, I'm working on getting it more layers deep, and I think I can, but there's still always going to be a top layer."

"Do you have any guesses for how long things could run without you?"

"Depends what you mean by 'things' and 'run' and whether there's a lot of robot attrition."

"Mostly I'm wondering how long your robots could reliably handle maintenance of a larger transportation system without your intervention."

"So, if the place is getting creamed by supervillains every month and robots are dying to that all the time, not long. In a hypothetical perfectly peaceful world Rete could probably do maintenance for, let's say Amtrak or the equivalent, for upwards of twenty years without me, and if it declined in capacity it'd still be able to handle hiring contractors for anything it couldn't manage alone."

"If it were possible to take out the entire system in one attack that might be a problem but generally villains actively targeting transit infrastructure are pretty rare. There are too many players with a vested interest in that not happening, on both sides of the law. Endbringers still do it obviously but we can keep anything valuable on the other earth and seal it off as needed?"

"Right, I'm not saying it's likely, I just don't have much sense of why you want robot trains at all and it could've been anticipating a train-wrecker coming through often enough to prompt tense union negotiations if you hired people to fix things. Normal trains are pretty good. Humans can maintain them."

"Mostly I'm just generally interested in finding ways to leverage powers for larger infrastructure projects - I think people gave up on trying too easily."

"My robot flock will probably be better at that in five years than it is now both in numbers and in progress on the layering thing. And maybe some vertical integration with materials suppliers."

"Hm, that's longer than we want to wait before having a Brockton to Montreal line, but if things go well there will be other lines to add."

"I reiterate that completely normal human people can and have built trains!"

"It costs billions of dollars normally."

"Well, if you were going to give me billions of dollars I too would put more work into it sooner."

"If you think you'd be able to do better than conventional tech at a similar price point we could possibly make that happen?"

"Now we're talking. You sort of led into it like you were wondering if I had the spare capacity to do it as, like, a favor."