He made her a slight warning sign.

“Dear Mother, let us defer questions till after dinner! Miss Diana! To your health!” And he held up his glass of champagne towards her. “You are looking remarkably well!—and both my mother and I are glad that the air of Switzerland agrees with you!”

Half pleased, half puzzled, Diana smiled her recognition of the friendly toast, but in her own mind, wondered what it all meant? Why did dear old Madame Dimitrius stare at her so much? Why did even Vasho, the negro servant, roll the whites of his eyes at her as though she were somebody he had never seen before? And taking these things into account, why did Dimitrius himself maintain such an indifferent and uninterested demeanour?

Nevertheless, whatever the circumstances might portend, she was more disposed to mirth than gravity, and the delicious timbre of her voice made music at table, both in speaking and laughter,—the music of mingled wit and eloquence, rare enough in a man, but still rarer in a woman. Very few women have the art of conversing intelligently, and at a dinner nowadays the chief idea seems to be to keep on “safe” ground, avoiding every subject of any real interest. But Diana was not particular in this regard,—she talked, and talked well. On this evening she seemed to throw herself with greater zest into the always for her congenial task of keeping her mysterious “employer” and his mother amused,—and Dimitrius himself began to feel something of the glamour of a woman’s fascination against which he had always been as he boasted—“spirit-proof.” His was a curious and complex nature. For years and years, ever since his early boyhood, he had devoted himself to the indefatigable study of such arts and sciences as are even now regarded as only “possible,” but “non-proven,”—and he had cut himself off from all the ordinary ambitions as well as from the social customs and conventions of the world, in order to follow up a certain clue which his researches had placed in his hands. Though his ultimate intention was to benefit humanity he was so fearful of miscalculating one line of the mathematical problem he sought to solve, that for the time being, humanity weighed as nothing in his scale. He would admit of no obstacle in his path, and though he was not a cruel man, if he had found that he would need a hundred human “subjects” to work upon, he would have killed them all without compunction, had killing been necessary to the success of his experiments. And yet,—he had a heart, which occasionally gave him trouble as contending with his brain,—for the brain was cool and calculating, and the heart was warm and impulsive. He had never actually shunned women, because they too, as well as men, were needful points of study,—but most of the many he had met incurred his dislike or derision because of what he considered their unsettled fancies and general “vagueness.” His mother he adored; but to no other woman had he ever accorded an atom of really deep or well-considered homage. When he advertised for a woman to help him in his experimental work, he did so, honestly because he judged a woman, especially “of mature years,” was of no particular use to anybody, or, if she did happen to be of use, she could easily be replaced. With an almost brutal frankness, he had said to himself: “If the experiment I make upon her should prove fatal, she will be the kind of human unit that is never missed.”

But Diana was an unexpected sort of “unit.” Her independence, clear perception and courage were a surprise to him. Her “mature years” did not conceal from him the fact that she had once been charming to look at,—and one point about her which gave him especial pleasure was her complete resignation of any idea that she could have attraction for men at her age. He knew how loth even the oldest women are to let go this inborn notion of captivating or subjugating the male sex,—but Diana was wholesomely free from any touch of the “volatile spinster,”—and unlike the immortal Miss Tox in “Dombey and Son,” was not in the least prone to indulge in a dream of marriage with the first man who might pay her a kindly compliment. And his dread of the possible result of his first experimental essay upon her was perfectly genuine, while his relief at finding her none the worse for it was equally sincere. Looking at her now, and listening to her bright talk and to the soft ripple of her low, sweet laughter, his thoughts were very busy. She was his “subject;” a living subject bound by her signed agreement to be under his command and as much at his disposal as a corpse given over for anatomical purposes to a surgeon’s laboratory. He did not propose to have any pity upon her, even if at any time her condition should call for pity. His experiment must be carried out at all costs. He did not intend to have any more “heart” for her than the vivisector has for the poor animal whose throbbing organs he mercilessly probes;—but to-night he was conscious of a certain attraction about her for which he was not prepared. He was in a sense relieved when dinner was over, and when she and his mother left the room. As soon as they had gone he addressed Vasho:

“Did you see?”

The negro inclined his head, and his black lips parted in a smile.

“It is the beginning!” said Dimitrius, meditatively. “But the end is far off!”

Vasho made rapid signs with his fingers in the dumb alphabet. His words were:

“The Master will perhaps be over-mastered!”