"_Vorwaertz_, Stampa!" repeated Bower, suddenly changing the ice ax to his right hand and stretching the left as far along the rope and as high up as possible. Simultaneously he raised the ax. Then, and not till then, did Spencer understand. Stampa must be on the point of relaxing his grip and preparing to descend. If Bower cut the rope with a single stroke of the adz, a violent tug at the sundered end would precipitate Stampa headlong into the crevasse, while there would be ample evidence to show that he had himself severed the rope by a miscalculated blow. The fall would surely kill him. When his corpse was recovered, it would be found that the cut had been made much closer to his own body than to that of his nearest neighbor. "Stop!" roared Spencer, all a-quiver with wrath at his discovery. Obedience to the climbers' law held the others rigid. That command implied danger. It called for an instant tightening of every muscle to withstand the strain of a slip. Even Bower, a man on the very brink of committing a fiendish crime, yielded to a subconscious acceptance of the law, and kept himself braced in his steps. The American was well fitted to handle a crisis of that nature. "Hold fast, Stampa!" he shouted. "What is wrong?" came the ready cry, for the rear guide had already driven the pick of his ax into the ice again after having withdrawn it. Then Spencer spoke English. "I happen to be watching you," he said slowly, never relaxing a steel-cold scrutiny of Bower's livid face. "You seem to forget what you are doing. Follow me until you have taken up the slack of the rope. Do you understand?" Bower continued to gaze at him with lack-luster eyes. All he realized was that his murderous design was frustrated; but how or why he neither knew nor cared. "Do you hear me?" demanded Spencer even more sternly. "Come along, or I shall explain myself more fully!" Without answering, the other made shift to move. Spencer, however, meant to save the unwitting guide from further hazard. "Don't stir, Stampa, till I give the order!" he sang out. "All right, monsieur, but we are losing time. What is Barth doing there? _Saperlotte!_ If I were in front----" Bower, who owned certain strong qualities, swallowed something, took three strides downward, and said calmly: "I was waiting to give Stampa a hand. He is lame, you know." Helen, of course, heard all that passed. She had long since abandoned the effort to disentangle the skein of that day's events. Everybody was talking and acting unnaturally. Perhaps the ravel of things would clear itself when they regained the commonplace world of the hotel. In any case, she wished the men would hurry, for it was unutterably cold in the crevasse. At last, then, there was a movement ahead.