Just back of where I now stand is the entrance or outlet to the tunnel through the wall.

It is closed, I suppose, by a swinging stone, like the one on the opposite side.

I saw that one opened--opened by some person concealed from view, as soon as the boy sang his bit of song which was the signal agreed upon.

And I was fool enough, after that warning, to walk straight through the tunnel! You're getting old, John Merrick; that's the only way I can account for your folly.

But Ferralti hasn't won the odd trick yet, and if I keep my wits about me he isn't likely to win." Thus ruminating, Uncle John searched the rocky wall carefully and believed he would know the place again, although which of the rough stones of its surface formed the doorway to the tunnel he could not guess.
A ledge of rock served as a path leading to right and left around this end of the valley, or "pocket" in the mountain, as it could more properly be called.