How the fare works: the rules of the train, explained

The rules you learn in the first act

1. Nobody boards by accident, but almost nobody boards on purpose

Most passengers wake aboard with no notion how they came to be there. A few see the train standing at a platform where no train is due, lit and full, and step onto it. The conductor treats both as a purchase. When Cora Marsh says she has no ticket, he corrects her: she stood on the platform for forty minutes, looked at the open door for four seconds, and got on anyway. “That's a purchase.”

2. Every door costs one true memory

The train has more carriages than anyone has counted. You may search any of them, and no one will hinder you. But each car you open costs you one memory: not a fact, not a date, not a name, but the kind you can walk around inside. Facts are worthless aboard and you may keep all of them. The transaction happens as the door slides open, and you choose nothing about it.

3. You will never feel it go

This is the rule that does the damage. There is no sensation, no gap, nothing to put your tongue in. What is gone leaves, in the conductor's words, “a smaller you, and the smaller you is quite comfortable and has no complaints.” The only way to learn what you have spent is to write your memories down before you spend them and read them back afterwards: if the words are there and nothing is behind them, that one has gone.

4. The fare is the person you would go back for

The train does not want memory in general. It takes the person you would return to the world for: a daughter, a brother, a mother, a wife. Someone who boards with nobody of that kind is, in the one currency the train recognises, destitute, and cannot open a single door. Book Three is largely about what such a person did instead.

5. To take someone off, you must claim them

Finding a passenger is not the end. To walk them through a door you must prove they are yours, and the proof is a memory, given up at the step. So the arithmetic every searcher eventually does is this: spend memories of the person to find the person, and arrive with at least one left to claim them with.

What the later books add

6. The wall is not a list of passengers. It is a ledger of what is left of them

Somewhere aboard is a warm room whose walls are covered, floor to a ceiling nobody has seen, in names: the Room of Forgotten Names. Every passenger is written there within seconds of boarding. A name is black when the person has spent nothing and goes thin as they spend. When it fades entirely, the person is still aboard, still pleasant, and has no more idea who they are than the wall does; there is nothing left for a claim to attach to.

7. A name can be inked back in, and it costs the same coin

Going over a faded name with a pen does nothing; the ink sits on the surface for a day and is gone. But if you stand in front of a stranger's name and give up a true memory of your own person, the wall takes it, puts it under the name, and the name comes back black. That passenger can then walk to a door and it will open, without anyone claiming them. They leave knowing nothing about who they were. But they leave.

8. You cannot spend on yourself

The wall will take a memory for any name but your own. This is why the rescue operation in the writing carriage exists, and why it can never rescue the people running it.

9. The deeper the spending, the dearer the repair

A person who has spent forty can be put back for one. Past two hundred, it takes three or four attempts, and the wall gives no part credit: an insufficient inking fades and the memories are gone anyway. Past three hundred there is no recorded case of anyone being put back at all.

10. Departed names come off clean

When a passenger leaves, their name vanishes from the wall with no residue, as if the plaster had never been written on. Which means a clean patch is evidence that somebody got off.

11. Whoever asks for the door pays, not whoever walks through it

Two people can travel together, and only the one who presses the button is charged. This is the loophole on which one character builds forty-five years of work.

12. There is a second currency

The doors, unlike the wall, will take any true memory of anyone you would go back for. A mother with a husband, a mother of her own and a house full of Sundays can spend all of those first, and keep her daughter. She will not know who she is at the end. But she will know the daughter. This is the trade at the centre of The Memory Fare.

What the train is

Nobody in the books finds out, and the series is honest about that. What Book Three establishes is where a spent memory goes: a corridor in the unmapped part of the train that the geometry has to go round, eleven feet wide, silent, and lined with stone that belongs to a railway cutting in Shropshire. It has been a fixed point for surveyors since at least 1856, and standing in it feels exactly like a spent memory feels from the inside: a warm shape with nothing in it.

The nearest thing to an answer is an opinion, recorded as an opinion, by a woman who spent forty-five years refusing to record opinions: “I think it is looking for something. I think it has been looking a very long time and has lost what for. I think it takes ours because it has none of its own left.”