'Very good,' Herbert answered drily; 'only mind, whatever you do, for Heaven's sake don't go and stumble and pull ME down on the top of you. It's the clear duty of a good citizen to respect the lives of the other men who are roped together with him on the side of a mountain.' They set to work again, in single file, with cautious steps planted firmly on the treacherous snow, to scale the great white slope that stretched so temptingly before them. Harry felt his knees becoming at every step more and more ungovernable, while Herbert didn't improve matters by calling out to him from time to time, 'Now, then, look out for a hard bit here,' or 'Mind that loose piece of ice there,' or 'Be very careful how you put your foot down by the yielding edge yonder,' and so forth. At last, they had almost reached the top of the slope, and were just above the bare gulley on the side, when Harry's insecure footing on a stray scrap of ice gave way suddenly, and he began to slip rapidly down the sheer slope of the mountain. In a second he had knocked against Paolo, and Paolo had begun to slip too, so that both were pulling with all their weight against Kaspar and the others in front. 'For Heaven's sake, man,' Herbert cried hastily, 'dig your alpenstock deep into the snow.' At the same instant, the chief guide shouted in Roumansch to the same effect to Kaspar. But even as they spoke, Kaspar, pushing his feet hard against the snow, began to give way too; and the whole party seemed about to slip together down over the sheer rocky precipice of the great gulley on the right. It was a moment of supreme anxiety; but Herbert Le Breton, looking back with blood almost unstirred and calmly observant eye, saw at once the full scope of the threatening danger. 'There's only one chance,' he said to himself quietly. 'Oswald is lost already! Unless the rope breaks, we are all lost together!' At that very second, Harry Oswald, throwing his arms up wildly, had reached the edge of the terrible precipice; he went over with a piercing cry into the abyss, with the last guide beside him, and Kaspar following him close in mute terror. Then Herbert Le Breton felt the rope straining, straining, straining, upon the sharp frozen edge of the rock; for an inappreciable point of time it strained and crackled: one loud snap, and it was gone for ever. Herbert and the chief guide, almost upset by the sudden release from the heavy pull that was steadily dragging them over, threw themselves flat on their faces in the drifted snow, and checked their fall by a powerful muscular effort. The rope was broken and their lives were saved, but what had become of the three others?