I nodded, wondering what in the world it all meant.

“And you get no clue from these facts?” he asked, a trifle surprised.

I searched every corner of my mind and imagination for some inkling of his meaning, but was obliged to admit that I understood nothing so far.

“Never mind, you will later.  And now,” he added, “we will go over the wood and see what we can find.”

His words explained to me something of his method.  We were to keep our minds alert and report to each other the least fancy that crossed the picture-gallery of our thoughts.  Then, just as we started, he turned again to me with a final warning.

“And, for your safety,” he said earnestly, “imagine now—­and for that matter, imagine always until we leave this place—­imagine with the utmost keenness, that you are surrounded by a shell that protects you.  Picture yourself inside a protective envelope, and build it up with the most intense imagination you can evoke.  Pour the whole force of your thought and will into it.  Believe vividly all through this adventure that such a shell, constructed of your thought, will and imagination, surrounds you completely, and that nothing can pierce it to attack.”

He spoke with dramatic conviction, gazing hard at me as though to enforce his meaning, and then moved forward and began to pick his way over the rough, tussocky ground into the wood.  And meanwhile, knowing the efficacy of his prescription, I adopted it to the best of my ability.

The trees at once closed about us like the night.  Their branches met overhead in a continuous tangle, their stems crept closer and closer, the brambly undergrowth thickened and multiplied.  We tore our trousers, scratched our hands, and our eyes filled with fine dust that made it most difficult to avoid the clinging, prickly network of branches and creepers.  Coarse white grass that caught our feet like string grew here and there in patches.  It crowned the lumps of peaty growth that stuck up like human heads, fantastically dressed, thrusting up at us out of the ground with crests of dead hair.  We stumbled and floundered among them.  It was hard going, and I could well conceive it impossible to find a way at all in the night-time.  We jumped, when possible, from tussock to tussock, and it seemed as though we were springing among heads on a battlefield, and that this dead white grass concealed eyes that turned to stare as we passed.

Here and there the sunlight shot in with vivid spots of white light, dazzling the sight, but only making the surrounding gloom deeper by contrast.  And on two occasions we passed dark circular places in the grass where fires had eaten their mark and left a ring of ashes.  Dr. Silence pointed to them, but without comment and without pausing, and the sight of them woke in me a singular realisation of the dread that lay so far only just out of sight in this adventure.