It seemed to him that, as he was at liberty, he should do anything that was in his power to free Boris.

Until he knew more of the lay of the land, he could not even make a real plan, but it was possible, he thought, that something that was in his mind might easily prove to be feasible.
It was easy, with his torch and the guiding arrows, to follow the devious, winding course of the passage.

He surmised that its ascents and descents, which seemed arbitrary and unreasonable as he pursued them, were due to other entrances than the one he knew.

It would be necessary, as he could understand, to have more than one means of getting in and out of such a passage.

And when he found himself at last going in a straight path which sloped easily downward, he guessed that he was beyond the house, and that he had come to a part of the passage that led to the outer world.
Here there was a trace of dampness, but nothing like what might have been expected in what was really a tunnel.