"We are near," he cried suddenly, after clambering up a steep rocky wall and surveying the horizon; then he held out his hands to his companions and drew them up after him. A new spectacle then presented itself. The opposite slope of the rocky ridge which they had just ascended was perfectly smooth and shiny, and encompassed the whole region in a semi-circle, forming a sort of basin, at the very bottom of which--and it was six hundred feet deep--lay a little mountain lake, the dark-green waters of which perpetually boiled and bubbled, though not a breath of air was stirring: perhaps it felt the ebb and flow of ocean. The opposite side of the rocky basin was formed by a gigantic chain of mountains, fringed only at its base by fir trees, and at the point where the two mountain systems met, a small stream in a deep bed trickled into the little mountain lake. The masses of ice which had fallen into the valley formed a crystal vault over this stream. "Whither are we going?" asked Clement, aghast. "To the source of that brook," returned Sange Moarte. "It has dug its way through the ice, and by following its course we shall come to the place we seek." "But how are we to get there? This rocky slope is as smooth as a mirror; if a man begins sliding down it there is no stopping till he plumps into the lake." "You have only to take care. We must lie on our backs and glide down sideways. Here and there you will find a tuft of Alpine roses to cling on to. But you've nothing to fear if you slide down barefoot. Do as I do." A hair-bristling pastime truly! Taking off their sandals they held on by their hands and feet to the smooth, shelving, stony wall, at the foot of which lay the darkly-gleaming, fathomless lake. They had already slided half-way down the incline, when from the mountain opposite arose a muffled, mysterious roar. They felt the cliff on which they lay quaking beneath them. "Ha! stay where you are," cried Sange Moarte, looking back at them. "An avalanche from the mountain opposite is approaching." And at the very next moment they could see a white ball descending from the immeasurably distant heights, plunging with mad haste down the mountain slope, tearing away with it whole masses of rock and uprooted pines, swelling every moment into a more tremendous bulk, and dashing down the decline in leaps of two hundred feet at a time into the valley below. "Heaven defend us!" cried the terrified Clement, clutching his guide with one hand and holding on to the rock with the other. "It is coming this way, and will overwhelm us all." "Keep still," cried Sange Moarte, seeing them inclined to clamber up again and thus expose themselves to the danger of a fall. "The avalanche will take the direction of that block of rock standing in its way, and will there either stop or disperse."