“There’s a little haze in the west,” remarked the lad, at length. “It might indicate the coming of a thunderstorm. That’s what is needed—a sudden, drenching thunderstorm. A gentle shower would help, but a regular cloudburst is needed. Of course, a sizzling rain would put the fire out in time, but it would take too long.” “Oh, I do hope it rains!” exclaimed Mary. Tom guided the _Hummer_ over the very center of the fire, which seemed to be burning in an area of forest and brush country several miles square in extent. Of course in the very center of the blaze no attempt was being made to fight it; that would have been too dangerous. It was on the edges of the ever-increasing circle that the men and boys were making the attack. Dropping down a bit, so Mary could see better, Tom pointed out where scores of the fire-fighters were trying to beat the flames to earth with long-handled wet bundles of rags, which from time to time they dipped in brooks and ponds. “It looks like a losing fight,” sighed the girl. “Oh, Tom, suppose the fire reaches Shopton!” “It won’t with the wind the way it holds now,” was the reply. “But of course we’d all feel better with the fire out.” He swung the machine around to take in another angle of the fire. “Isn’t there anything you can do, Tom?” asked Mary. “This is terrible!” Tom was himself wondering if he could not be of service instead of merely looking on from his vantage point of safety in the air. He had invented an aerial fire-fighting machine, but this, with its chemical bombs, had been disposed of, and there was none on hand at Shopton. “I might drop some army bombs down and try to blow up a big, bare area which would bring the fire to a stop,” said Tom. “But it would take some time to get ready for that, and they may have it out in a few hours. No, I’m afraid I can’t do anything just now. But we had better——” Tom was about to say he had better start back with Mary when, with a suddenness that was startling, the motor of his plane went dead and the machine began to drop toward the heart of the forest fire. “Oh, Tom!” cried Mary. “Don’t go down so close! It’s dangerous!” CHAPTER XII A RING OF FIRE KNOWING little of the actual working of aeroplanes, Mary did not realize what the stopping of the engine meant. She thought Tom had simply shut it off, as he often did, so the noise would not interfere with their hearing of what was going on below. “Go on back up, Tom!” cried the girl. “I don’t want to go so close.” “I’m afraid there’s no help for it,” stated Tom grimly. “What—what do you mean?” “I mean the motor’s stopped. Something has gone wrong with it. We’re making a forced landing. Goodness knows what the outcome will be!” But Tom said the last to himself as he saw the forest fire seemingly rushing nearer and nearer. It looked as if he would crash down in the midst of the burning trees.