meddling whelp, Motor Matt. The Dutchman won't get away from us so easily as you will, Ferral, I can promise you that. And before Motor Matt is many days older, I'll show him what it means to cross Brady's path."

Hector Brady, like his son, was a fair-spoken villain, but none the less dangerous for all that. As he ceased talking, he started to step from the cockpit to the aisle of deck between the cabin top and the sailboat's side.

"'Vast, there!" roared Ferral, twitching at the lanyard about his neck and bringing out a sheath knife. "Keep your offing, both you sharks, or you'll find a knife between your ribs. You've got us out in the lake, but you haven't my money yet, and you're not going to cut up rough with my raggie here. I got him into this mess, and I'm going to see him out of it."

A boat hook, dropped by the skipper when he was pushing the nose of the boat away from the pier, lay on the deck close to Carl's feet. He bent down and picked it up.

"Oof he makes some foolishness mit me," averred Carl, "you bed my life I vill haf somet'ing to say aboudt dot meinseluf. I had some hunches all der time," he harped ruefully.

Brady, Sr., did not come out of the cockpit just then. "There are four of us against you," said he sternly, "and if you've got as much sense as I give you credit for, you'll not resist. All I want of you, Ferral, is your money. If what you told my son is true, your uncle is a rich man. He'll give you another roll for the asking and never miss it. Are you a pard of King's?"

"I'm all that," declared Ferral. "I owe Motor Matt a debt I can never repay."

"And I owe him one I'm going to repay," said Brady, with a black look. "He stole my air ship from me, and I've got to buy it back. It's no more than justice that I take part of the money from you—if you're such a good pal of King's. I didn't think, any more than Hector, that the thing was going to fall out like this, but my luck must be taking a turn for the better."

"Skipper," shouted Ferral, looking at the Norwegian over the heads of the two Bradys, "put about and take us ashore! These scoundrels are trying to rob me."

The skipper, however, only returned a stolid look.

"You'll be hauled over the coals for this!" threatened Ferral.

Carl had been on the point of saying something, but off toward the west and south, over the stern of the sailboat, he beheld an object that amazed him and aroused a faint hope.

The object seemed to hang in the sky like a black cylinder. It was the Hawk, there could be no possible doubt about that, but was the Hawk sailing out over the lake or merely traveling over the City of Chicago? So far away was it that Carl could not tell whether it was coming or going. Could it be possible that Motor Matt was bringing the air ship in the direction of the Christina? It seemed too much of a coincidence to be true, and yet it was hardly stranger than the circumstances which had enveloped Ferral in the net spread by the two Bradys.

Carl, although the discovery of the air ship stretched his nerves to tightest tension and filled him with fluttering hope, kept the news of his discovery to himself. If the Hawk was really heading lakeward, Brady, if he knew it, might realize the possibilities of escape which it would afford the two boys and take measures to keep the Christina away from the air ship.

"No one is going to be hauled over the coals, Ferral," said Brady. "When we put you ashore, it will be in a place from which it will take you a good long while to get back to Chicago. Before you get back, I'll have a man buy the Hawk, and I and my friends will make a quick getaway to parts unknown. The Hawk means liberty for me, for I can't dodge around on the ground and keep clear of the police much longer. Are you going to hand that money over, or have we got to take it away from you?"

Shifting his sheath knife to his left hand, Ferral drew the roll of bills from his pocket and stowed it snugly in the breast of his blue shirt.

"If you get this money you'll have to take it," said he defiantly, "and if that two-faced sea cook you say is your son comes too close to me, I'll get him on the point of this dirk."

Covertly, Carl was watching the round swaying speck in the heavens. That it was round, proved that he was looking toward the end of the gas bag, which, seen lengthwise, would have been of cigar-shaped proportions; and the fact that the object was growing larger by swift degrees, proved that it was coming closer to the sailboat.

"Enough of this foolishness," scowled Brady, drawing a revolver and leveling it at Ferral over the end of the cabin. "Take that money out of your shirt and throw it this way. If you make a miss throw and land it in the lake, I'll plug you for that just as quick as I would for not throwing it at all. It's up to you," he added warningly, "and I'm not going to wait all day."

Carl, in the moment of silence that intervened, suddenly hurled the boat hook with all his strength. The move was entirely unexpected on Brady's part, and he was caught unawares. The handle of the hook struck his arm a violent blow, knocking the weapon out of his fingers and dropping it overboard.

A yell of rage went up from Brady.

"Kick off your shoes, Tick," whispered Carl excitedly. "Ven I gif der vort, chump indo der lake. I know vat I know, und I dell you it vas all righdt. Do schust vat I say, aber don'd say somet'ing."

The presence of the air ship was unknown to everyone on the sailboat except Carl. To Ferral it looked like suicide to jump into the lake, with no other boat anywhere in sight.

"I'll kill you for that!" bawled Brady to Carl.

The Dutch boy paid no attention. He had already kicked off his shoes and pulled off his coat. Holding his coat in his hand, he leaped to the top of the cabin and began waving it frantically.

The Bradys, the Norwegian and the Swede swept the surface of the lake with their eyes. Even then their glances fell too low to give them a glimpse of the Hawk.

Ferral had got rid of his shoes, although he was still reluctant about taking to the water. Carl did not give him much time to consider the matter, but grabbed him by the arm and, when the little craft heeled to a strong gust of wind, pulled him overboard.

CHAPTER IV.

RESCUED.

All those on the Christina were astounded at the move made by the two boys.

"Leave 'em in the water for a while!" shouted Brady, Sr. "I guess that'll take the ginger out of 'em. Don't be in any hurry, captain, about turning around."

The captain could not have turned very quickly, even if he had wanted to. With all sail set, the Christina was driving through the water at race-horse speed. It would take time, and she would inevitably have to get a long way from the boys before she could be put about.

Both Carl and Ferral were good swimmers and had little difficulty in keeping themselves afloat, hampered though they were with their wet clothing.

"We're in for it now, Carl!" gurgled Ferral. "That sailboat will put about and we'll be hauled aboard—then that swab of a Brady will have us just where he wants us." Ferral rose in the water, shook his head to clear his eyes, and peered after the Christina. "They're coming around now," he added.

"Led dem come aroundt all vat dey blease," sputtered Carl; "Matt vill pull us oudt oof der vet pefore dey ged here."

"Matt?" echoed Ferral.

"Look oferheadt vonce, Tick."

Ferral took a look upward. Rushing toward that part of the lake and swooping downward like a huge bird was an air ship. The strange craft was almost upon him and Carl. Two men were leaning over the guard rail of the car on each side; both held coiled ropes in their hands, and one of them was shouting instructions to Matt, who was in charge of the motor.

The Christina