“He’s cross!” she declared. “_Chère Madame_, he’s cross! It is a positive miracle! The cool scientist and calm philosopher is in a bit of a temper!” Madame Dimitrius gave a rather regretful and unwilling assent. Truth to tell, the gentle old lady was more bewildered than satisfied with certain things that were happening, and which perplexed and puzzled her. As, for example, when Diana took her arm and affectionately escorted her from the dining-room to the drawing-room, she could not refrain from wondering at the singular grace and elegance of the once plain and angular woman,--she might almost be another person, so different was she to the one who had arrived at the Château Fragonard in answer to her son’s advertisement. But she had promised to say nothing, and she kept her word, though she thought none the less of the “Flaming Sword” and the terrific problem her son had apparently determined to solve. Meanwhile, Diana, having settled her cosily by the fire with her knitting, ran quickly off to obey the command of Dimitrius. She had never been asked to go near the laboratory since her first visit there, and she hardly knew how to find the corridor leading to it. She looked for the negro, Vasho, but though he had waited upon them at dinner he was now nowhere to be seen. So, trusting to memory and chance she groped her way down a long passage so dark that she had to feel the walls on both sides to steady her steps as she went, and she was beginning to think she had taken an entirely wrong direction, when a dull, coppery glitter struck a shaft of light through the gloom and she knew she was near her goal. A few more cautious steps, and she stood opposite the great door, which glowed mysteriously red and golden, as though secret fire were mixing living flame with its metal. It was shut. How could she open it?--or make her presence outside it known? Recollecting that Vasho had merely laid his hand upon it, she presently ventured to do the same, and soon had the rather terrifying satisfaction of seeing the huge portal swing upwards yawningly, disclosing the interior of the vast dome and the monstrous Wheel. But what a different scene was now presented to her eyes! When first she had entered this mysterious “laboratory” it had been in broad daylight, and the sun had poured its full glory through the over-arching roof of crystal,--but now it was night and instead of sunshine there was a cloud of fire! Or, rather, it might be described as a luminous mist of the deep, rich hue of a damask rose. Through this vaporous veil could be seen the revolving Wheel, which now had the appearance of a rainbow circle. Every inch of space was full of the radiant rose haze, and it was so dazzling and confusing to the sight that for a moment Diana could not move. With a vague sense of terror she dimly felt that the door had closed behind her,--but steadying her nerves she waited, confident that Dimitrius would soon appear. And she was right. He