overturned; then came the swirl and bubbling hiss of a flood that gleamed darkly under the golden lamps and swiftly rose towards them, bearing upon its surface white arms with outstretched hands gripping at the empty air, and gauzy robes which half hid gleaming limbs, white faces with wildly-staring eyes, and teeth that grinned between tight-drawn lips so lately smiling; strong swimmers fighting for another moment's breath, and one by one dragged down by many hidden hands: then the sharp hiss of swift-quenched flames, then darkness, and the stifling of sobbing groans into silence, and after that only the sibilant undertone of waters rushing swiftly past smooth walls through utter night.

"Dear me!" the Professor heard himself say as he sat up and rubbed his eyes, "what on earth can be the matter with me? Egypt—the Queen—Palace of Pepi—bridal feast of Nitocris and Menkau-Ra—yes, yes, of course I remember it all now. She made me impersonate Nefer in the mummy-case, and then, when she had frightened her guests half out of their wits, she avenged her lover by opening the sluice-gates and drowning the lot, herself included. A rare device, that of old Pepi's, for getting rid of hospitably entertained enemies. Not quite in accordance with our modern ideas of sport, I'm afraid, but in those days we thought a good deal more of effectiveness than sport. Good heavens! What sort of nonsense am I talking? Dreaming, I suppose."

He stopped as the reflection of a brilliant flash of lightning lit up his window, and bursts of rain dashed upon the panes.

"Ah yes, of course, that's it! Quite in accordance with the theory of dreams. It's only the difference between a thunder-shower and the Nile flood. The Genius of Dreams could easily account for the rest. Certainly this apparatus that we call our brain plays some very curious tricks with us sometimes. I suppose this is one of them. And yet if ever there was a dream that seemed like reality that one did. The Mummy and the long-dead Nitocris back to life! By the way, I wonder whether that flagon was really there, and whether there was any wine in it? If there was, perhaps I took too much of it. Ah, there's the rain again!

"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.

He could see their faces distinctly in profile. They were of the classic Coptic type which so persistently reproduces the features of the old Egyptians as we see them outlined in the wall-paintings of the temples and the half-mutilated carvings and statues. The window of the study was open, but the door was shut; so was the door of his own room, but for all that he distinctly heard the man say to the woman in Coptic, which, curiously enough, sounded as familiar to his ears as the faces seemed to his eyes:

"Neb-Anat, it is gone! These heathen ravishers have not been content with stealing the body of our Queen from its sacred resting-place and bringing it here, whither we have traced it with so much labour. See, it has been stolen again; hidden, no doubt, so that the servants of the King could not find it. It may be that even we have been suspected and watched, in spite of all our care. Yet it must be found, or the doom that may not be revoked will be ours."

"Even so, Pent-Ah," replied the woman in a soft, musical voice which well suited the comeliness of her face; "but though the priceless treasure has been taken from its casket, it cannot have been carried out of the house, for you know that every approach has been watched closely since it was brought here. Come, in this house it must be, and to find it is our task. Every one is asleep; take off thy shoes and let us search."

She took off her own shoes as she spoke, and he saw the man do the same. Then, as the man opened the door and they passed out of the study, the picture vanished from the mirror.

Amazement at what he had seen and heard—the disappearance of the Mummy, the presence of the man and woman, evidently charged with what they believed to be the sacred mission of stealing it back again, and their evident purpose of searching the house for it—instantly gave place to a quick thrill of fear.

His daughter's bedroom was on the same floor as the study, only a couple of doors away round the corner of the landing. These people would search every room. What if she had not locked her door securely, or if they had some means of opening it? She was the living image of the dead Nitocris. He did not dare to think of what might happen to her. Would these new-found, strangely-given powers of his suffice to protect her? If not, he would