MISQUAH — The “loons” tier — invented earlier this month by librarian Ruth Aune specifically and solely to stay one rung ahead of fourth-grader Brynn Solberg — lasted four days before Solberg cleared it, leaving Aune once again standing at the top of a ladder she built that morning with nothing above her and a child looking up.

Aune has declined, this time, to announce the next tier at all, having concluded through bitter and repeated experience that naming a rank only tells Solberg precisely where to aim and how fast to run. “I’m keeping the next one to myself,” she said. “Last time I announced it, she had it by the weekend, and I watched her do it, and I aged. This time she’s climbing in the dark, toward a thing only I know the name of. Maybe that slows her down. It will not slow her down. But a woman has to try something, and uncertainty is the only tool I have left.”

Asked about the strategy directly, Solberg reported, without looking up from a book, that she had already read four more since clearing the loons and was “ready whenever Mrs. Aune is,” and that she suspected the next tier would be “wolves, or bears, because those are bigger than a loon, unless it’s a moose, but I think moose is too silly even for the summer program.” Aune, told of the guess, declined to confirm it, deny it, or appear in any way to have heard it — which Solberg, no fool, correctly read as meaning she was close, and went back, with visible purpose, to her book.