and reflected for a long time.

A wood, even a small wood, is not an easy thing to search minutely;
but he provided himself with some practical tests in the matter.
In one sense the very density of the thicket was a help;
he could at least see where anyone had strayed from the path,
by broken and trampled growths of every kind. After many hours'
industry, he had made a sort of new map of the place;
and had decided beyond doubt that some person or persons had
so strayed, for some purpose, in several defined directions.
There was a way burst through the bushes, making a short cut
across a loop of the wandering path; there was another forking
out from it as an alternative way into the central space.
But there was one especially which was unique, and which seemed
to him, the more he studied it, to point to some essential
of the mystery.

One of these beaten and broken tracks went from the space under
the peacock trees outward into the wood for about twenty yards
and then stopped. Beyond that point not a twig was broken nor
a leaf disturbed. It had no exit, but he could not believe
that it had no goal. After some further reflection, he knelt
down and began to cut away grass and clay with his knife,
and was surprised at the ease with which they detached themselves.
In a few moments a whole section of the soil lifted like a lid;
it was a round lid and presented a quaint appearance, like a flat cap
with green feathers. For though the disc itself was made of wood,
there was a layer of earth on it with the live grass still growing there.
And the removal of the round lid revealed a round hole, black as
night and seemingly bottomless. Paynter understood it instantly.