Thomas spent three days composing the letter, tearing up more drafts than he'd attempted since the earliest, most desperate weeks after the anomaly first stranded him.
He couldn't ask outright. Do I have a sister was not a question a son could send his mother without inviting an entire cascade of concern he had no honest way to answer — not from a distance of three hundred years and one impossible world, writing through a connection that had never once, in four years, allowed her to ask him a single question in return.
He settled, eventually, on something oblique enough to survive the asking. I've been thinking about the old house lately, he wrote, and trying to remember everything about growing up there. Tell me about the year Sarah was born — I want to remember it properly, the way you do.
He sent it with his hands unsteady, and spent the following days in a state of quiet, private dread he didn't fully share even with Victoria, though she read enough of it in his face to keep close without needing to ask.
The answer came four days later, warm and entirely unsuspicious, exactly as he'd hoped and feared in equal measure.
Oh, that whole year is such a blur now! I remember your father pacing the hospital waiting room like he'd never done this before, even though he'd already been through it once with you. You were so excited to be a big brother — you kept asking when she'd be old enough to play catch with you, which took considerably longer than you wanted, if I recall. Sarah's grown into such a wonderful young woman. I know you two don't talk as often as either of us would like, with how far away you've moved, but I hope you know how proud she is of you, even from a distance.
Thomas read it standing perfectly still in the garden, the cold winter air doing nothing to dull the particular vertigo of reading, in his own mother's warm, unsuspecting voice, a whole fifteen years of a relationship that had, as far as his own memory could attest, simply never happened.
Sarah. A name now, a face he still couldn't summon, a whole childhood of shared holidays and sibling squabbles that existed, apparently, as vividly and completely in his mother's mind as any of his own genuine memories did in his.
Victoria found him there an hour later, the letter still clutched in his hand, and read the whole shape of his silence before he'd managed to explain any of it properly.
"She's real to her," he said finally. "Whatever Sarah is, wherever she came from, my mother doesn't just remember a lake trip or a set of neighbors wrong. She's built an entire relationship, years long, with a daughter I have absolutely no memory of ever meeting. She thinks we don't talk often because I've 'moved far away.' She's constructed an entire, coherent explanation for my own silence that has nothing at all to do with the truth."
"Do you think Sarah knows? Whoever, whatever she is — does she believe she has a brother too?"
"I don't know. I don't know if that question even makes sense, Victoria. I don't know if she's a real person living a real life who happens to believe I exist, or whether she's — I don't have words for what the alternative would even mean. A ripple. An echo. Something that exists because the shape of the world bent around the absence I left behind, and needed someone to fill it." Thomas felt his own composure fraying at the edges, the accumulated weight of every small, growing wrongness finally converging into something too large to carry with his usual careful stoicism. "I keep thinking about the relay's warning. Deviation cascade approaching threshold. I understood that as a warning about my own ending, Victoria. I'm starting to wonder if it was warning me about something considerably larger than just myself."
Victoria held him a long while in the cold garden, saying nothing further, offering only the plain, steady comfort of her presence against a fear too vast and strange for either of them to properly resolve with words alone.
"Whatever Sarah is," she said finally, "your mother loves her, the same way she's always loved you. I don't think that love is any less real for whatever strange mechanism produced it. I think, if anything, that might be the one small mercy hiding inside all of this — that even a world reshaping itself around your absence still found room, somehow, to fill the gap with something worth loving rather than something worth grieving."
Thomas held onto that thought through the rest of the difficult evening, though the cold, hollow shock of it lingered considerably longer than any of the previous discrepancies had managed — a whole sister, real enough to love and be loved, existing in a world he could no longer fully claim to understand the shape of, four years and one entire impossible lifetime removed from anything he could still call reliably, certainly home.