For a moment it seemed to the terrified lads that their cry had not been heard, yet just when they began to despair three horses dropped behind, and as the boys came up with them they recognized the two ranch owners and Pete. "Take Horace, Pete; Snider, Tom; I'll take Larry," commanded Mr. Wilder, and each of the men leaped their horses to seize the bridle of the boy indicated. Not more than two miles behind them was the terrible wall of fire. In front of it coyotes and all other animals of the plains were In full flight, their cries of fear or pain as they fell victims to the all-devouring flames now and then rising above the sullen roar. "Oh, it's gaining! it's gaining!" wailed Horace. "Don't look behind. Keep your eyes in front and _ride_!" commanded his father. Sparks borne by the wind began to fall all about, now and then starting blazes which the cowboys put out by beating with their blankets where they could, yet none checked his speed. To the hot air was added smoke, and men and horses were breathing with difficulty, gasping and coughing. "If you've got handkerchiefs, jam them in your mouths!" cried Snider. Nearer, ever nearer drew the wall of flame. It seemed to the chums that they must be breathing fire, so did the air burn their mouths. Time and again they swayed in their saddles and would have fallen had it not been for the men beside them, who had let go the bridles to steady the boys, at the same time rowelling their own mounts. Just when it seemed to the boys that the shirts on their backs would burst into flames a shout went up from in front: "The river! The river!" "One more spurt, everybody!" Gamely men, boys and horses responded. "Right over the bank! Don't stop!" bellowed Pete. Ignorant of the height, caring little, eager only to gain the water, the boys felt their horses leap through the air and the next minute were sputtering and gasping as they sank below the surface of the river. CHAPTER XXI A RIDE FOR LIFE Quickly the horses swam for the shore, and as the Elkhorn was only deep for a few rods, it was not many minutes before the cowboys were shaking and removing their wet garments. But the boys were oblivious of their condition. In open-mouthed wonder they stared at the spectacle presented by the flames from whose devouring fury they had so narrowly escaped. The wall of fire had in reality been farther away than it had seemed. For several minutes it advanced, the tongues of flames towering in the air. A moment the livid wall paused as it reached the brink of the river, while jets of fire reached out as though striving to clutch the men who had escaped. Then seemingly bent on overtaking them, the flames leaped over the edge, devouring the brush and grass to the water's edge, where, loath to admit defeat, the flames flickered uncertainly and then died away, leaving nothing but a pall of smoke to mark their course of destruction.