Mark stared open-mouthed. Again he and the bewildered Elaine exchanged glances. And instinctively their hands reached out across the aisle, to join in love's tender clasp. The happiness of utter confidence and peace glowed in their eyes. Then, still holding the girl's hand, Mark turned back to the professor. His brows knitted with incredulity. "My God!" he exclaimed half to himself. "Could it be possible? Could I have done such a thing?" Abruptly, he halted. "No!" he clipped decisively. "There are other angles to be considered. Vance, for instance. You say he went with me through the time mirror--" "Yes." The savant nodded slowly. "That, Mark, is the final proof. The evidence beyond contradiction. The thing that convinces me--" "Proof? Evidence? I don't get it." "You will recall, Mark, that Jerbette's memoirs said Baron Morriere was killed in that final battle with Jacques Rombeau?" "Yes. Of course. What's that got to do with it?" The scientist leveled a trembling finger at the window across the room, through which the sunlight still streamed. Never had he been more impressive. Solemn conviction gleamed in his blue eyes. "Not five minutes before you and Elaine aroused from your state of suspended animation," he said, "Adrian Vance--still in a coma--sprang from his bed to that window and hurled himself to his death!" Horror widened the two young people's eyes. Elaine's face was pale. But understanding now was flooding through Mark. He nodded slowly. "You can't change history!" he said.