Tropical storms are apt to come up in a hurry, and inside of a quarter of an hour it was raining in torrents. They had crossed the bridge of a small stream and now they found shelter under the shed of a long warehouse which was old and empty. “This is certainly a downpour,” remarked Professor Strong, when they were out of it. “See how the water is rushing along the roadway.” He was right, the rain was coming down as if there had been a cloudburst. There was a little lightning and thunder, but not enough to cause alarm. But the heavy fall of water made the very roof of the old warehouse sag. “I never saw the water come down like this before,” observed the professor, as the downfall continued. “It will certainly wash things out in the valley.” For over an hour the heavy fall of rain continued. It was coming through the roof of the warehouse and they had trouble in keeping even comparatively dry. But now the thunder was rolling up to the northward, and it slacked a trifle. “Hark!” cried Sam, presently. “What did you hear?” came from several of the others. “Thought I heard somebody calling for help. Listen!” They listened, and the cry was repeated. It came from down a side trail which joined the highway just in front of the old warehouse. “Somebody is in trouble down there!” ejaculated Mark. “Let us go and investigate.” Without waiting to obtain permission from the professor, he started down the side trail, with the others following. The trail led downward into something of a bottom, full of loose rocks, with here and there a patch of mud. “I see her!” cried Mark, presently, as he turned a corner of the trail and came in sight of a wide and shallow stream, backed up by a rocky hill and a tangle of forest growth. “It’s a woman on a hut, and she is in danger of drowning!” Mark was right. In the middle of the wide stream was a native hut which had been washed away from somewhere and become lodged in between the rocks. On the frail building, which looked as if it might go to pieces at any instant, sat an old colored woman, shrieking for help at the top of her voice. The old woman had with her two children, a white girl and a white boy of perhaps five or six years of age, and to these she was clinging desperately. “Save us! save us!” cried the colored woman, in Spanish. “We’ll do what we can,” called back the professor. “Hold tight till we can get to you.” “How are you going to get to her?” demanded Hockley. “That water is running like mad.” “I think we can leap from rock to rock,” suggested Sam. “Let’s take hold of hands,” came from Frank. “One of you run back for that rope which we saw at the warehouse,” said the professor, and Hockley did so, for the lank youth had no desire to risk his life in that foaming and dashing torrent.