Stern brought to mind some of Professor Raoul Pictet's experiments with animals, in which the Frenchman had suspended animation for long periods by sudden freezing. This method seemed to answer, in a way, the girl's earlier questions as to how they had escaped death in the many long winters since they had gone to sleep. Again, they tried to imagine the scenes just following the catastrophe, the horror of that long-past day, and the slow, irrevocable decay of all the monuments of the human race. Often they talked till past midnight, by the glow of their stone fireplace, and many were the aspects of the case that they developed. These hours seemed to Stern the happiest of his life. For the rapprochement between this beautiful woman and himself at such times became very close and fascinatingly intimate, and Stern felt, little by little, that the love which now was growing deep within his heart for her was not without its answer in her own. But for the present the man restrained himself and spoke no overt word. For that, he understood, would immediately have put all things on a different basis--and there was urgent work still waiting to be done. "There's no doubt in my mind," said he one day as they sat talking, "that you and I are absolutely the last human beings--civilized I mean--left alive anywhere in the world. "If anybody else had been spared, whether in Chicago or San Francisco, in London, Paris or Hong-Kong, they'd have made some determined effort before now to get in touch with New York. This, the prime center of the financial and industrial world, would have been their first objective point." "But suppose," asked she, "there _were_ others, just a few here or there, and they'd only recently waked up, like ourselves. Could they have succeeded in making themselves known to us so soon?" He shook a dubious head. "There may be some one else, somewhere," he answered slowly, "but there's nobody else in this part of the world, anyhow. Nobody in this particular Eden but just you and me. To all intents and purposes I'm Adam. And you--well, you're Eve! But the tree? We haven't found that--yet." She gave him a quick, startled glance, then let her head fall, so that he could not see her eyes. But up over her neck, her cheek and even to her temples, where the lustrous masses of hair fell away, he saw a tide of color mount. And for a little space the man forgot to smoke. At her he gazed, a strange gleam in his eyes. And no word passed between them for a while. But their thoughts--? CHAPTER XIII THE GREAT EXPERIMENT The idea that there might possibly be others of their kind in far-distant parts of the earth worked strongly on the mind of the girl. Next day she broached the subject again to her companion.