betty nelson reached the bank of the river and stopped. she could go no farther for the muddy water stretched itself at her feet. but her boat—the trim little gem—was moving slowly up the stream under the influence of the mysterious something that was towing it away from the girls.

"oh!" cried grace. "what can we do? betty—mollie! we must stop it."

"yes; but how?" asked mollie. she and the others had followed betty to the shore.

"we must find another boat, and catch the gem!" cried amy. "it isn't going very fast."

"if we only could!" murmured betty, looking helplessly around. but no other boat was in sight. "we must do something," she went on. "we'll be marooned if we stay here!"

"but what can be towing our boat?" asked mollie. she stood on the bank, nervously twining her fingers in and out, weaving them back and[119] forth as she always did when puzzled or alarmed. "is it the current taking it away, betty?"

"but it's going against the current," grace pointed out. "some animal must have become entangled in the anchor or painter, betty. an alligator, perhaps."

"that's it!" cried mollie. "an alligator is running away with our boat. oh, betty!"

"it may be that," admitted the little captain, as she gazed after her craft. "i didn't think of it, but that's probably what it is. i don't see the beast above the water, though. do you, girls?"

there was nothing visible except part of the anchor rope that extended from the ring-bolt in the forward deck, over the stem and slanting down into the water.

"the alligator may be swimming just below the surface," was mollie's opinion. "he may come up pretty soon, and we can throw stones at it. that's it, betty. we must stone the creature and make it let go. come on!"

betty laughed. the others looked at mollie curiously.

"she—she's hysterical," murmured grace.

"i am not!" protested mollie indignantly.

"but the idea of throwing stones at an alligator!" cried grace. "why, its hide will turn a bullet!"[120]

"oh!" exclaimed amy blankly. "then what can we do? we have no bullets!"

"it isn't going very fast," observed mollie as she watched the boat moving slowly up the river. "we can run along the bank after it, and maybe the beast will let go, or run ashore with the gem. then we could get it."

"who—the boat or the alligator?" asked betty, who seemed to be in better spirits now, even in the face of trouble.

"the boat, of course."

"then speak of the gem as 'her' and the alligator as 'it,'" betty directed. "but i believe mollie's plan is the only one we can adopt. we must follow along the bank. only i hope, if the alligator does let go, it won't be in the middle of the river, for then our boat would float down, and it might lodge on the other shore. then we would be as badly off as we are now. oh, what a predicament! we seem to be getting into nothing but trouble of late."

"never mind," consoled amy. "maybe this will be the last."

"it's a comfort to think so, anyhow," agreed grace. "i wonder why an alligator ran off with our boat?"

"a mere accident," was betty's opinion. "probably the creature was swimming along[121] shore, and became entangled in our anchor rope. it may be as much frightened as we are distressed. but come on, if we're going to try to get the boat."

stumbling over the uneven way, the girls raced along the river bank. sometimes the boat appeared to be coming close in shore, and again it would veer out.

"i've just thought of something!" exclaimed amy as they came up nearly opposite the boat, for it was being towed more slowly now, as though the creature having it in charge found it harder work.

"then do, for goodness sake, tell us what it is," demanded mollie. "i'm about played out."

"if we threw stones on the other side of the alligator—i mean across, between him and the other shore—it might scare him over this way."

"oh!" screamed grace. "don't you dare scare him over here!"

"i didn't mean right here," went on amy. "i only meant farther in toward this shore. then he might run aground and we could wade out and get the boat."

"wade in the water that has an alligator in it!" cried grace with a shudder. "never!"

"well, it might be a good plan to try," spoke betty. "i see what amy means. when we were[122] little, and used to play with toy boats, if one went out too far we used to throw stones in the water beyond it, and the waves would sometimes send it ashore. now, if we did that, the alligator might think someone on the other bank was throwing things at him, and he would come over here. it's worth trying."

"i am certain i can't throw straight," complained grace.

"oh, well, this isn't a ball game," said mollie. "any sort of throwing will do for an alligator. come on, now, all together."

in spite of her protest, grace managed to do fairly at the stone-throwing. in fact the outdoor girls were what their name implied—they could do many things that outdoor boys could do, and throwing stones was one of their accomplishments. they had not played basket ball for nothing.

a shower of missiles fell into the water on the far side of whatever creature was towing the gem. for a few minutes no effect was produced, and then the creature under water did seem to veer over toward the shore where the girls were slowly walking along.

"gracious! if he really comes here!" cried grace, getting ready to beat a retreat.

"i'm afraid there's not much danger," spoke[123] betty, in a low tone. "he seems too fond of our boat."

"throw more stones!" directed mollie, and another shower of small rocks sailed through the air to fall with many splashes into the turbid water.

there was a swirl in the river just in front of the gem, as though the creature towing it objected to the treatment it was receiving. and then, as the girls, anxiously watching, prepared to send another volley of stones, amy uttered a cry, and pointed up the river toward a small point of land that jutted out into the stream.

"look!" she cried. "a man in a boat!"

they all gazed to where she indicated, and beheld not a man, but a ragged youth standing up in a broad bottomed scow, poling himself down stream. he was headed directly for the gem.

"oh, he is just in time!" cried mollie. "he'll get our boat for us!"

"call to him!" directed grace. "i'm so nervous that i can't speak above a whisper."

mollie raised her voice in an appeal for help.

"hello, there!" she called. "our boat! right in front of you! can you get it? scare away the alligator! it's towing our boat off! please get it!"

the ragged youth looked up, startled, and[124] glanced from the boat, seemingly moving up stream without any visible propelling agency, to the four girls on the shore. he seemed much surprised, and acted, as betty said afterward, as though he would like to run away. she called to him:

"look out for the alligator! don't get into danger!"

the ragged youth now seemed to comprehend what was wanted of him. he poled his clumsy craft toward the gem and peered down into the water to see what manner of creature was at the other end of the anchor rope. then he waved his pole at the girls, as though to reassure them, and edged nearer the motor boat.

"all right!" he called, in a quick, nervous manner. "i see him. i'll get him for you."

"gracious—i wonder if he means the boat or the alligator?" said mollie. "i hope he understands that we don't want both—only the boat."

"oh, he'll know," declared betty. she was eagerly watching the actions of the ragged youth in the scow.

suddenly he drew something from his pocket and held it close to the water, leaning over the edge of his craft.

there was a puff of smoke, a flash of fire, and a report that sounded very loudly to the girls.[125]

"oh!" cried grace, covering her ears with her hands.

"be quiet, silly!" exclaimed betty. "it was the only thing he could do. he shot at the alligator."

again the revolver of the ragged youth sounded loudly and, a little cloud of smoke floated over his boat. then he shouted:

"i hit him! i hit him!"

he was seen to reach over with his pole, and fish for something in the water.

"i hope he isn't going to bring it ashore—the alligator, i mean!" cried mollie. "we want the boat. get the boat!" she called to the ragged youth.