In dimensions it reminded me of the tunnels beside the opal path with which I was already familiar, but it was otherwise different. There was no vertical rod, such as that which had drawn the eyes, and stayed the pursuit of the Frog-Mouths. There was no difference between floor and walls, but all were marble-smooth, and hard, and cold. They were opalescent, but of a kind and colour which I had not seen previously. The sides and roof were of the dim green of the under-surface of an arching wave, and like a wave they curved over, differing from the upright walls and flat ceiling of the earlier tunnels. The floor gave an impression of dark green depths through which we could have seen to the remoteness of the earth’s interior, had the faint light allowed it. We had ceased to think as we moved forward, so that I might once again give to my companion the benefit of the sight she lacked, and it must have been my own volition that caused us to take a few steps within the entrance of the cavity. But as we did so, her thought broke sharply across my own, “You need show no more: I can see here.” It was a relief that did not lessen the marvel. She showed me that the blackness still fell like a curtain over the very mouth of the cavity, where I looked out into sunlight, but the gloom within was alike to both of us, and in the relief of this renewed equality we sat down, not very prudently, against the wall of the passage, forgetting its potential dangers in the pleasure of needed rest, and in the necessity of reconsidering our position. “The question is,” I began immediately, “shall we continue the plan we made before we knew that this tunnel existed, or shall we do better to attempt to descend it?” “It is one question, among several,” my companion answered, “but it is hard to answer. We have some facts now of which we were ignorant when we decided two nights ago. If we exchange our thoughts at once, we shall make confusion only. Let us think separately till we have each resolved what is best, and have made our reasons clear to ourselves. Then, should we differ, and either prove unable to convince the other, I will give way very willingly.” I assented to this, knowing it to be unlikely that such a difference would arise or continue, and we remained silent for a considerable time, for my own thoughts were chaotic, and I was anxious not to interrupt the exhaustive logic of the mind beside me.