"Why, we are safe here. The water will never rise to this height." "I know it! I know it!" groaned Tom, falling back in his seat and paling because of the pain from his arm, which he had twisted. "But don't you see? There are many down the valley who won't know of this until too late. Why, they can't see it at the bridge--at Culm Falls-- until the flood is right upon them." "It's true!" gasped Helen. "What shall we do?" "We must warn them--we can warn them, can't we?" demanded Ruth. "This car runs so fast--you control it so well, Helen. Can't we warn them?" "Try it, Sis!" shouted Tom. "You can do it!" And already his sister, setting her teeth hard upon her lower lip, was backing and turning the motor car. In twenty seconds they were dashing off upon the track over which they had so recently come--on the road down the valley with the flood following fast behind them. CHAPTER X THE RACE The two girls on the front seat of the flying automobile were not prepared for racing. Of course, Ruth Fielding had no proper automobile outfit, and Helen had not expected such an emergency when she had started with her crippled brother for this afternoon run. She had no goggles, nor any mask; but she had the presence of mind to raise the wind-shield. Already they could have heard the steady roaring of the advancing flood had not the racing motor car drowned all other sounds. There was, however, no need to look behind; they knew the wave was there and that it was sweeping down the valley of the Lumano with frightful velocity. Indeed, they were not at all sure for those first few miles whether they were traveling as fast as the flood, or not. Suppose the wave should reach and sweep away the bridge before they could cross the river? The thought was in the mind of both Helen and Ruth, whether Tom, on the rear seat, considered it or not. When they finally shot out of the woods and turned toward the toll-bridge, all glanced around. From here the upper reaches of the Lumano were plainly revealed. And extending clear across the valley was the foam-crested wave charging down upon the lowlands, but a number of miles away. Here was the first house, too. They saw a man and woman and several children out front, staring at the automobile as it raced down the road. Perhaps they had been called from the house by the vibration of the bursting dam. Tom sprang up in the car and pointed behind him, yelling: "The flood! The flood!" It is doubtful if they heard what he said; and they, too, were on a knoll and likely out of the reach of the water. But the three in the automobile saw the whole family turn and run for the higher ground behind their house. They understood the peril which menaced the whole valley.