But it was not until the end of the week, when Vance approached him with purpose in his eyes and manner, that Henriot knew his fears unfounded, and caught himself trembling with sudden anticipation — because the invitation, so desired yet so dreaded, was actually at hand. Firmly determined to keep caution uppermost, yet he went unresistingly to a secluded corner by the palms where they could talk in privacy. For prudence is of the mind, but desire is of the soul, and while his brain of today whispered wariness, voices in his heart of long ago shouted commands that he knew he must obey with joy.

It was evening and the stars were out. Helouan, with her fairy twinkling lights, lay silent against the Desert edge. The sand was at the flood. The period of the Encroaching of the Desert was at hand, and the deeps were all astir with movement. But in the windless air was a great peace. A calm of infinite stillness breathed everywhere. The flow of Time, before it rushed away backwards, stopped somewhere between the dust of stars and Desert. The mystery of sand touched every street with its unutterable softness.

And Vance began without the smallest circumlocution. His voice was low, in keeping with the scene, but the words dropped with a sharp distinctness into the other’s heart like grains of sand that pricked the skin before they smothered him. Caution they smothered instantly; resistance too.

“I have a message for you from my aunt,” he said, as though he brought an invitation to a picnic. Henriot sat in shadow, but his companion’s face was in a patch of light that followed them from the windows of the central hall. There was a shining in the light blue eyes that betrayed the excitement his quiet manner concealed. “We are going — the day after tomorrow — to spend the night in the Desert; she wondered if, perhaps, you would care to join us?”

“For your experiment?” asked Henriot bluntly.

Vance smiled with his lips, holding his eyes steady, though unable to suppress the gleam that flashed in them and was gone so swiftly. There was a hint of shrugging his shoulders.

“It is the Night of Power — in the old Egyptian Calendar, you know,” he answered with assumed lightness almost, “the final moment of Leyel-el-Sud, the period of Black Nights when the Desert was held to encroach with — with various possibilities of a supernatural order. She wishes to revive a certain practice of the old Egyptians. There may be curious results. At any rate, the occasion is a picturesque one — better than this cheap imitation of London life.” And he indicated the lights, the signs of people in the hall dressed for gaieties and dances, the hotel orchestra that played after dinner.

Henriot at the moment answered nothing, so great was the rush of conflicting emotions that came he knew not whence. Vance went calmly on. He spoke with a simple frankness that was meant to be disarming. Henriot never took his eyes off him. The two men stared steadily at one another.

“She wants to know if you will come and help too — in a certain way only: not in the experiment itself precisely, but by watching merely and —” He hesitated an instant, half lowering his eyes.

“Drawing the picture,” Henriot helped him deliberately.

“Drawing what you see, yes,” Vance replied, the voice turned graver in spite of himself. “She wants — she hopes to catch the outlines of anything that happens —”

“Comes.”

“Exactly. Determine the shape of anything that comes. You may remember your conversation of the other night with her. She is very certain of success.”

This was direct enough at any rate. It was as formal as an invitation to a dinner, and as guileless. The thing he thought he wanted lay within his reach. He had merely to say yes. He did say yes; but first he looked about him instinctively, as for guidance. He looked at the stars twinkling high above the distant Libyan Plateau; at the long arms of the Desert, gleaming weirdly white in the moonlight, and reaching towards him down every opening between the houses; at the heavy mass of the Mokattam Hills, guarding the Arabian Wilderness with strange, peaked barriers, their sand-carved ridges dark and still above the Wadi Hof.

These questionings attracted no response. The Desert watched him, but it did not answer. There was only the shrill whistling cry of the lizards, and the sing-song of a white-robed Arab gliding down the sandy street. And through these sounds he heard his own voice answer: “I will come — yes. But how can I help? Tell me what you propose — your plan?”

And the face of Vance, seen plainly in the electric glare, betrayed his satisfaction. The opposing things in the fellow’s mind of darkness fought visibly in his eyes and skin. The sordid motive, planning a dreadful act, leaped to his face, and with it a flash of this other yearning that sought unearthly knowledge, perhaps believed it too. No wonder there was conflict written on his features.

Then all expression vanished again; he leaned forward, lowering his voice.

“You remember our conversation about there being types of life too vast to manifest in a single body, and my aunt’s belief that these were known to certain of the older religious systems of the world?”

“Perfectly.”

“Her experiment, then, is to bring one of these great Powers back — we possess the sympathetic ritual that can rouse some among them to activity — and win it down into the sphere of our minds, our minds heightened, you see, by ceremonial to that stage of clairvoyant vision which can perceive them.”

“And then?” They might have been discussing the building of a house, so naturally followed answer upon question. But the whole body of meaning in the old Egyptian symbolism rushed over him with a force that shook his heart. Memory came so marvellously with it.

“If the Power floods down into our minds with sufficient strength for actual form, to note the outline of such form, and from your drawing model it later in permanent substance. Then we should have means of evoking it at will, for we should have its natural Body — the form it built itself, its signature, image, pattern. A starting-point, you see, for more — leading, she hopes, to a complete reconstruction.”

“It might take actual shape — assume a bodily form visible to the eye?” repeated Henriot, amazed as before that doubt and laughter did not break through his mind.

“We are on the earth,” was the reply, spoken unnecessarily low since no living thing was within earshot, “we are in physical conditions, are we not? Even a human soul we do not recognise unless we see it in a body — parents provide the outline, the signature, the sigil of the returning soul. This,” and he t............