Suddenly from the shore there shot up into the air a long, curving streak of fire. Then came a dull, booming explosion, and the dark sea was lit up for a moment. The darkness which followed seemed even more black than before.

"A rocket!" shouted Frank. "They're giving us a signal."

"Gee," said Jimmy, after a moment, "it feels good to know they're thinking of us, but it doesn't help much."

"There goes another one!" Rocket after rocket now split the air, marking distinctly the place for which they were heading. The boys redoubled their efforts, swimming side by side with a steady over-arm stroke. Something of the horror of the darkness and the mystery of the rolling waters was taken away by the thought that the people on shore knew of their distress and were trying to help. But little could those on shore know how really bad their plight was. The rockets were being sent up as a guide to a disabled boat. They could not know that the long, brilliant sweep of light was being watched by two boys struggling for their very lives on the surface of the water itself.

"We must be halfway there, don't you think?" said Jimmy, in a labored breath.

"We've come a long distance, for the lights look brighter. Can't you see lights moving on the shore?" returned Frank. "Let's stop and look."

The boys stopped, trod water and raised themselves high as they reached the crest of a wave. Frank was right. The lights they saw were the lights of many lanterns, for the whole town of Seawall had turned out. Boats were being manned and people ran hither and thither on the shore peering out to sea.

"Come on now," shouted Frank, who felt heartened by what he had seen, "let's break the record for the rest of the distance," and, putting down his head, he tore ahead, followed by Jimmy more slowly, but just as determined. They had been plugging away for perhaps five minutes when Frank heard a cry behind him. He stopped instantly and listened.

"Jimmy," he called shrilly, "Jimmy!"

There was no answer. Frank, with a sweep of his hand, turned face about and dashed back over the course he had come. A dozen strokes brought him to his companion, whose white face on the surface was his only guide. "What is it, Jimmy, old fellow?" he cried, as he drew alongside.

"Cramp," said Jimmy feebly. "It came suddenly in my side. I couldn't swim and I couldn't take breath enough to yell out. It just doubled me up."

"Here," said Frank, "rest on me and try to straighten out," for Jimmy was still doubled up. Jimmy lay back and rubbed his side vigorously, while Frank slipped an arm under his head and with the other kept afloat. "It was my fault," he said encouragingly, as Jimmy rubbed the kink out of his side. "That rocket made me crazy to get to shore."

"No, it wasn't your fault, at all," replied Jimmy, in a stronger tone. "It was the cold water. I felt it a while back and thought I could fight it off by working hard, but it got me at last, struck suddenly just like a knife. I'm all right now; come on," and, turning over on his face again, he struck out weakly. Frank was at his elbow watching for any weakness, but as Jimmy continued going smoothly he lengthened out his own stroke and soon they were back at the old swing. The halt, however, although only for a few minutes, had lost them ground, for during the time that they were not swimming the tide had carried them steadily ahead—but not shoreward. They were still far from safety.

Now they changed their course a little more to the left so as to cut across the current, and bore steadily for the lights which seemed to increase in size. They wasted no more words except occasionally one would say: "You there?"

The answer would come back from the other: "O. K." or "All right." They had no extra breath to spare. The distance was surely lessening, but so was the strength of these two heroic lads. How heavily swung their arms! Every few minutes they changed the stroke. Sometimes it was one arm over, sometimes the other, and again it was the trudgeon or the breast stroke, whichever offered a little rest. Both were nearly exhausted, but with the courage of despair they swam on, neither admitting to the other that he was almost done for. They did not dare to float, for that meant being carried beyond their haven of safety. If they passed the little indentation where Seawall lay it was good-by to everything, for they would be carried into the wide waters of the outer bay and must miserably perish. This knowledge spun their failing strength out to the last slim thread.

Away ahead the lights danced merrily. It seemed to Frank as if there were millions of them jumping up and down and swinging sideways. How friendly they looked, but how utterly useless to help! How deadly heavy his arm felt! There was no force left in him. How nice it would be to lie still and rest! He stopped swimming and sank. The cold under-current chilled him and awakened him to the fact that he was giving up. "I won't give up! I won't give up!" he said between his clenched teeth, and he struck out stronger than before. Jimmy was splashing feebly behind.

"We're nearly there, old fellow," gasped Jimmy.

"Nearly," returned Frank. "Keep it up. Let's shout." They stopped and shouted, but it was scarcely more than a croak and could not have been heard fifty yards. "Let's swim," said Jimmy, "shouting is no good out here." His voice was scarcely more than a whisper. Again they resumed their weary drive ahead.

Suddenly out of the darkness between them and the shore came a hail:

"Ha-yo, ha-yo, ha-yo!"

Instantly the boys stopped swimming and turned their faces in the direction of the sound.

"Ha-yo, ha-yo, ha-yo!" came the call again, this time nearer. They tried to answer the heartening hail but had not strength enough to send their voices far. They stood in the water close together and with straining eyes tried to pierce the darkness. Then in the momentary lull of rushing waters they heard a drumming.

"A motor boat!" cried Frank joyously. "And I see a light. It's coming this way. Oh, it is going to pass us! Let's yell!"

Together the two raised as loud a shout as they could.

In a moment the drumming stopped.

Again the two lads in the water shouted: "Here! here! here!"

The drumming began and the light at the bow, which showed plainly now, although the boat itself was still hidden, swung and lurched as the motor boat swept around in a curve. With rescue in sight the boys threw their last energy into a fusillade of shouts and soon, "Ha-yo, where are you?" came a hail from the boat.

"Look out, look out, you'll run us down," yelled the boys.

A bell rang; the motor stopped and cut silently through the waves only a few yards away.

"Here, here!" shouted Frank.

"Great CÆsar!" said a voice from the boat, "it is some one in the water. Stop her quick," as the boat was driving past the boys with her momentum. "Back her! Back her!" yelled the voice now in great excitement. "We've found them. They're in the water."

In a less time than it takes to tell it the captain had maneuvered the boat to within reaching distance of the two in the water. Strong hands reached over the sides and quickly pulled them to safety. Neither could stand. They sank down into the bottom of the boat. Frank looked up and saw his father standing over him.

"Back to Flat Rock, quick," gasped Frank. "Quick, there are two boys out there!"

"Why, Flat Rock is under water at this time of the tide," said the man at the helm wheel.

"Not yet. Oh, not yet! We left two boys there, and they will be washed off in a few minutes if you do not hurry."

Instantly the captain ordered full power ahead, and away the boat shot in the direction of the lonely rock. The two lying in the bottom of the boat were made as comfortable as possible, and between them they told the story of what had happened since they put out from Turner's Point on that eventful night.

As the boat neared the rock the men aboard raised a great shout and were surprised to hear a feeble cry from what seemed to be the surface of the water. Maneuvering carefully, guided by the calls from the water, the boat crept nearer and nearer to the sounds. No sign of a rock was visible, but the strong light at the bow showed two lads standing, their hands clasped together, knee-deep in water. They were on the very highest point of the rock. Quickly they were pulled into the boat, chilled almost to death by the long exposure. Like Frank and Jimmy, however, both Peters and Bates were soon wrapped in the coats of the men aboard, and made as warm as possible.

"Now," said Frank, "the only thing to be done is to find the Black Duck."

"We'll land you boys first," said the captain, and he drove his boat for Seawall, while the steady purr of the motor deepened into a roar. The waves shot away from her bows in a shower of foam as she raced ahead.

What a yell went up from the Seawall people as the boat neared the Pier, and the glad news was shouted over the water that the boys were safe and sound! The rescued quartette were quickly put ashore. As they touched the float, queer figures that they were, all bundled up in the coats of the men, shouting was heard from the water. "We've found them!" called a voice.

And even as they waited, in spite of the urgings to hasten to the house and dry clothes, a motor boat slipped into the circle of light thrown by the big lamp on the end of the Pier, and behind it came the Black Duck on the end of a tow line! And in the boat sat Lewis and Codfish quite calm and collected. They had been picked up by one of the searching parties.

You can imagine what a reunion took place that night in the Armstrong house! Even Peters, the cause of some of the trouble, was welcome; but that individual was none too comfortable, and was only too glad when his father's automobile drew up at the door to carry him to his own home. It was a night of jubilation, and the whole of Seawall joined to make a celebration of the wonderful feat of the two swimmers.