Thomas began keeping the unsent letters in the summer of the sixth year.
It started without any decision behind it. He wrote his mother a reply one Sunday, as he always had, and the phone did what it had always done with his replies — accepted the text, offered no confirmation, gave no indication whatsoever that anything had gone anywhere. He had been doing this for six years. He had never once known whether a single word of it arrived.
That particular Sunday, for no reason he could identify, he did not close the message. He saved it instead, into the drafts folder, where it sat as a small grey line of text under a heading that read Drafts (1).
The next week he saved that one too.
Drafts (2).
He didn't tell Victoria for two months, and when he did, he found it considerably harder to explain than he'd expected.
"It's not that I think they're reaching her," he said. "I've never thought that. She's never once answered anything I've written — not a single reference, in six years, to anything I've said. Whatever this connection is, it runs one direction and always has."
"Then why keep them?"
"Because—" He stopped, and started again. "Because a letter I send is gone. It's a thing I did once, into nothing, and there's no evidence afterward that I did it. A letter I save is still there. I can open it. I can read what I said to her in March." He looked at the small grey list. "It's the only part of this whole arrangement I have any control over at all. I can't make her real. I can't stop the number falling. I can keep a record of having tried to talk to my mother, and read it back, and know I did that."
Victoria took the phone from him — she could see it easily now, had been able to for years — and scrolled the list with an expression he couldn't read.
Drafts (9).
"May I?"
He nodded.
She read one, and then another, and then set it down and put her hand flat on the table for a moment before she spoke.
"You tell her about me," she said.
"Every week. She has no idea who you are and I've described you to her fifty times." Thomas found his voice was not entirely steady. "I tell her about the towers, and about Wat's knees, and I told her when Joan was sick and I told her when Joan got better. It's the only place I get to be a son. Everywhere else in my life I'm the man who has to know what to do."
Victoria did not say anything for a while.
"Keep them," she said at last. "All of them. And Thomas — put them in the Codex. Not the text, if you'd rather not, though I'd read them and I think Joan will one day. Put down that they exist, and where, and that they were never sent, and why you kept writing anyway."
"Why?"
"Because in forty years someone in this valley is going to be grieving somebody and doing something that feels foolish about it — talking to a grave, keeping a chair empty, writing letters into nothing." She met his eyes. "And I would like them to be able to read that the man who built this place did exactly the same thing, every Sunday, for years, and did not consider it foolish. That's worth more than the metallurgy, Thomas. I'd take that page over the whole rail section."
He wrote it that night, and the drafts kept accumulating, and by the end he had rather a lot of them.