midnight
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 .