Before there were rules, there was only the first visitor, who did not know yet what she was doing.
She went back to her daughter's seventh birthday party. A summer afternoon, the garden strung with paper. Her daughter was seven years old and running between the other children and laughing at something Vera could no longer remember by the time she went back to find it.
She arrived at the edge of the garden, at the gap in the hedge. She could see her daughter across the lawn. The child was mid-sentence, arms wide, explaining something to the small girl beside her with great seriousness.
Vera raised her hand.
Her daughter stopped. Not fully stopped. She did not fall or cry or look afraid. She stopped the way a pond stops when something touches its surface, the way a reflection touched goes still before it recovers. Her arms came down. She looked at the gap in the hedge where Vera was standing. Her face had an expression Vera could not interpret, something between recognition and something the body registers before the mind does.
Then the moment split. Not in any visible way. But Vera felt it: the past pulling around the interruption, the afternoon trying to continue and finding it could not, the children not quite in the right positions anymore, the party going on around a small stillness at its center where her daughter stood looking at the hedge.
Vera was sent back immediately.
It took three years and many registrars to understand what had happened. The past can hold a witness. It cannot hold a presence. A witness is a kind of nothing, the way a shadow is a kind of nothing: it falls across the moment without changing the light. But a presence changes the light. And the party, already over, already complete, had no room left in it for something that tried to belong there.
So: silence. No movement toward. No signal, no wave, no sound. Not because the past is fragile, but because what is finished cannot receive what is still open. The visitor may watch. The visitor may not arrive.
Vera's daughter grew up and never mentioned the afternoon to anyone. Whether she remembered it or whether the moment closed over it cleanly, the registrars could not say. This is the one question the practice has never been able to answer.