heavy and sorrowful as a mass of requiem, and I conjured images of strange shapes gathering fast amidst the reeds, beside the wash of the river.
In the morning, from the moment that I set foot in the breakfast-room I felt that the unknown plot was drawing to a crisis; the professor's face was firm and set, and he seemed hardly to hear our voices when we spoke.
"I am going out for rather a long walk," he said, when the meal was over. "You mustn't be expecting me, now, or thinking anything has happened if I don't turn up to dinner. I have been getting stupid lately, and I dare say a miniature walking tour will do me good. Perhaps I may even spend the night in some little inn, if I find any place that looks clean and comfortable."
I heard this, and knew by my experience of Professor Gregg's manner that it was no ordinary business or pleasure that impelled him. I knew not, nor even remotely guessed, where he was bound, nor had I the vaguest notion of his errand, but all the fear of the night before returned; and as he stood, smiling, on the terrace, ready to set out, I implored him to stay, and to forget all his dreams of the undiscovered continent.
"No, no, Miss Lally," he replied, still smiling, "it's too late now. Vestigia nulla retrorsum, you know, is the device of all true explorers, though I hope it won't be literally true in my case. But, indeed, you are wrong to alarm yourself so; I look upon my little expedition as quite commonplace; no more exciting than a day with the geological hammers. There is a risk, of course, but so there
