“It has been a wonderful experience,” she went on slowly. “Not that I would care to repeat it—Oh, Tom!” She suddenly gave a gasp of fear and covered her eyes with her hands as a blinding flash of lightning seemed actually to shoot through the cavern. It was followed a second later by a crash of thunder which made even Tom Swift, used as he was to experimenting with big guns, jump. “Here comes the rain!” he cried. At that moment the storm broke with almost tropical fury, the big drops pelting down like hail on the burning trees, bushes and such dry leaves as had accumulated from the previous fall. “This will douse the blaze,” went on the young inventor. Certainly, no forest fire could continue in the face of such odds as a violent rain storm—and this storm was violent. Seldom had Tom seen it rain so hard. He and Mary stood in the entrance to the cave and watched the drops pelt down. They could observe the fire in front of them die away, the blaze flickering out and then the smoke ceasing. “I guess those fire-fighters are glad of this!” observed Tom, as he remembered the hardworking men and boys. “Indeed, yes,” agreed Mary. For an hour or more the downpour continued, and every vestige of the forest fire was extinguished when at last the muttering of the thunder died away and the fierce glow of the lightning faded from the blackened clouds. Tom stepped outside the cave and looked about him. In the distance he could hear the loud murmuring of the brook, now turned into a good-sized stream. “Come on, Mary,” he called. “It’s all over. We might as well start. Your mother may be worried about you. I’ll find that boat and we’ll soon be in Shopton.” “Oh, I do wish I had a comb or something!” exclaimed the girl as she emerged from the cavern, trying to pin her hair back to keep it out of her eyes. “You look fine!” declared Tom, and he really meant it. “I can’t help it, anyhow,” Mary said, smiling slightly. “Thanks, Tom.” The boat was found where Tom knew it to be hidden—he had used it on some of his excursions with Ned—and soon he and his companion were riding in comparative comfort down the swift little stream. They passed through a region where the forest fire had eaten its devastating way, but now the danger was over, the rain having soaked and drenched the woods. In due time Tom and his companion reached the outskirts of Shopton, and then, knowing Mary would like a little privacy, he went to the nearest telephone and called a taxicab from the town garage. It came out to get him and Mary, and a little later she was safe at home. “Oh, Mary! I’ve been so worried about you!” cried Mrs. Nestor. “Where have you been?” “Oh, aeroplaning, falling, climbing out of trees, forest-firing, thunder and lightning, boating and floating—those are just a few of our activities this afternoon,” replied Mary, with a little excited laugh. “What does she mean, Tom?” asked the bewildered lady.