"By the way now, suppose that this fourth dimension that has puzzled so many of us is, after all, duration? If so, it would solve a great many problems, because it would be possible to be and not to be at the same time, and, therefore, for two bodies to occupy the same space. That would be perfectly easy of supposition to the being to whom time and eternity were one. Yes, I believe that when the great problem is solved, it will be found that the fourth dimension is duration, extending in all directions like the circumference of a circle, the edges of a cube, and the curves of the conic sections.
"Yes, I really do think I have got it at last, and that confounded Mummy has taught it me. Still, I don't think I ought to speak as disrespectfully as that of a young lady who has been dead for the last fifty centuries or so and has come back. Yes, that is it. It is duration."
Perfectly satisfied for the time being with this solution, he turned over on to his right side—for, to his disgust, he found that he had been lying on his back, a most pernicious position where dreaming is concerned—and went to sleep. Half an hour later he was awakened by another heaven-shaking crash of thunder.
CHAPTER IV
THIEVES IN THE NIGHT
This time he was very much awake. In fact, his sense of wakefulness seemed almost superhuman. His faculties were preternaturally alert, and he had a feeling of what might properly be called mental extension—it was not exaltation—- which seemed to widen his mental vision enormously. Problems which had puzzled him to desperation suddenly became as obvious as the first axioms of geometry. In short, he felt as though he had become a new man, re-born, or re-incarnated, into another world which contained the one he had so far lived in, but which was infinitely vaster in some undefined way which was not yet plain to him.
He lay for some time thinking over the extraordinary happenings of the evening and his dream, which he remembered with astonishing exactness of detail. Then a sudden turn of thought carried his mind to the subject of miracles, apparitions, ghosts, and mathematical impossibilities such as squaring the circle and doubling the cube—and to his amazement he found that the impossible of yesterday had become the possible—nay, the almost absurdly obvious of to-night.
He went on thinking and wondering until he began to half-believe that he was dreaming again, so he got up and switched on the electric light. Then he turned involuntarily towards the wardrobe, which, as usual, had a long mirror running down the middle of it. To his amazement he did not see himself reflected in it. The mirror seemed to have vanished, and in its place was a window looking into his study.
He saw the mummy-case leaning up against the wall, but it was empty. In front of it stood a man and a woman. Both were plainly, almost meanly, dressed; the man in a tightly-buttoned black frock-coat and baggy grey trousers; the woman in a plain gown of dark stuff, and a shawl which was draped round her head and shoulders in somewhat Eastern fashion.