They were now as impatient to descend as they had been to climb upward, and even more so; for the brightness of the day had departed, and ominous clouds were gathering about them. The air was bitterly cold; and, with their few minutes' cessation from violent exercise, they were chilled to the bone. So they hastened to retrace their rugged way, sliding, leaping, hanging by their hands, and dropping from ledge to ledge, taking frightful risks in their eagerness to escape the threatened storm, or at any rate to meet it in some more sheltered spot. If they could only reach the shelf-like ledge, at the farther end of which Binney Gibbs awaited them, they would feel safe. They had nearly done so, but not quite, when the storm burst upon them in a fierce, blinding, whirling rush of snow, that took away their breath and stung like needles. It seemed to penetrate their clothing. It bewildered them. It was so dense that they could not see a yard ahead of them. They had already started to cross that long, sloping snow-field, beyond which lay the rocky shelf. To go back would be as dangerous as to proceed. They could not stay where they were. The deadly chill of the air would speedily render them incapable of maintaining their foothold.