Frank adjusted the wires and a moment later the vehicle's motor was roaring normally. The housing was
put back on, Chet's tools were returned with thanks, and the four boys set off once more.
'Let's hope nothing more happens before we get home,' Biff said with a wry laugh.
'I'll second that,' Joe said emphatically.
For five minutes the cyclists rode along in silence, their thoughts partly on the passing scenery, but mostly
on the mystery in which they had become involved.
Joe's mind was racing with his throbbing motorcycle. In a few minutes he had far outdistanced his
brother. Frank did not dare go any faster because of the telescope strapped onto his handle bars.
Presently Joe reached a spot in the road where it had been cut out of the hillside on the right. There was
a sharp curve here. The motorcycle took it neatly, but he and Biff had scarcely reached the straightaway
beyond when they heard a thunderous sound back of them.
'What's that?' Joe cried out.
Biff turned to look over his shoulder. 'A landslide I' he shouted.
Rocks and dirt, loosened by recent heavy rainstorms, were tumbling down the steep hillside at terrific
speed.
'Frank!' Joe cried out in horror. He jammed on his brake and disengaged the engine. As he ran back to
warn his brother, Joe saw that he was too late. Biff had rushed up and both could only stare helplessly,
their hearts sinking.
Frank and Chet came around the corner at good speed and ran full tilt into the landslide. Its rumbling
sound had been drowned out by the pounding surf and their own roaring motor.
The two boys, the motorcycle, and the telescope were bowled over by the falling rocks and earth. As the
rain of debris finally stopped, Joe and Biff reached their sides.
'Frank! Chet!' they cried out in unison. 'Are you hurt?'
Frank, then Chet, sat up slowly. Aside from looking a bit dazed, they seemed to be all right. 'Rock just
missed my head,' Frank said finally.
'I got a mean wallop on my shoulder,' Chet panted gingerly, rubbing the sore spot.
'You fellows were lucky,' Biff spoke up, and Joe nodded his intense relief.
'How about the telescope?' Frank asked quickly. 'Take a look at it, will you, Joe?'
The battered carrying case, pushed out of the straps which had held it in place on the motorcycle, lay in
the road, covered with stone and dirt. Joe opened the heavily lined box and carefully examined the
telescope.
'It looks all right to me,' he said in a relieved voice. 'Of course we won't know for sure until we try other
eyepieces in it. But at least nothing looks broken.'
By this time Frank and Chet were standing up and Biff remarked, 'While you two are getting your
breath, Joe and I can take the biggest rocks out of the way. Some motorist may come speeding along
here and break his neck or wreck his car unless this place gets cleaned up.'
'Oh, I'm okay,' Chet insisted. 'The rock that hit me felt just like Bender, that big end on the Milton High
team. He's hit me many a time the same way.'
Frank, too, declared that he felt no ill effects. Together, the boys flung rock after rock into the field
between the road and the water and, in pairs, carried the heavier rocks out of the way.
'Guess we're all set now,' Frank spoke up. 'Biff, I'm afraid you're going to be late getting home.' He
chuckled. 'Who is she?'
Biff reddened a little. 'How'd you guess? I have a date tonight with Sally Sanderson. But she's a good
sport. She won't mind waiting a little longer.'
Again the four boys straddled the motorcycles and started off. A few minutes later a noise out in the
ocean attracted Frank's attention and he peered across the rolling sweep of waters. A powerful
speedboat came into view around the base of a small cliff about a quarter mile out. It was followed at a
short distance by a similar, but larger craft. Both boats were traveling at high speed.
'Looks like a race!' Joe called out. 'Let's watch it!'
The Hardys ran their motorcycles behind a clump of trees and stopped, then walked down to the shore
line.
The boats did not appear to be having a friendly speed contest, however. The first boat was zigzagging in
a peculiar manner, and the pursuing craft was rapidly overtaking it.
'See! That second boat is trying to stop the other one!' Frank exclaimed.
'It sure is. Wonder what's up,' said Joe tensely. 'I wish that telescope was working. Can any of you
fellows make out the names on the boats?'
'No,' the others chorused.
The two men standing in the bow of the pursuing craft were waving their arms frantically. The first boat
turned as if about to head toward the shore. Then, apparently, the helmsman changed his mind, for at
once the nose of his boat was pointed out into the ocean again.
But the moment of hesitation had given the pursuers the chance they needed. Swiftly the gap between the
racing craft grew smaller and smaller until the boats were running side by side. They were so close
together that a collision seemed imminent.
'They'll all be killed if they aren't careful!' Frank muttered as he watched intently.
The lone man in the foremost craft was bent over the wheel. In the boat behind, one of the two men
suddenly raised his right arm high. A moment later he hurled an object through the air. It landed in back
of the engine housing in the center of the craft. At the same time the larger boat sped off seaward.
'What was that?' Chet asked. 'I-'
Suddenly a sheet of flame leaped high into the air from the smaller boat. There was a stunning explosion
and a dense cloud of smoke rose in the air. Bits of wreckage were thrown high and in the midst of it the
boys saw the occupant hurled into the water.
Swiftly the whole boat caught fire. The flames raced from bow to stern.
'That man!' shouted Frank. 'He's alive!'
The boys could see him struggling in the surf, trying to swim ashore.
'He'll never make it!' Joe gasped. 'He's all in.'
'We've got to save him!' Frank cried out.
CHAPTER IV
The Rescue
THE Hardy boys knew that they had no time to lose. It was evident that the man in the water had been
injured by the explosion and could not swim, much longer.
'We'll never reach him!' Chet said, as the four boys dashed across the rocks and grass to the shore.
Suddenly Frank cried out, 'I see a rowboat up on the beach.' His sharp eyes had detected a large
rowboat almost completely hidden in a small cove at the bottom of the cliff. 'We'd make better time in
that!'
A huge rock jutting out of the water cut the cove off from the open part of the beach.
'We'd have to go up to that ridge and then down,' Joe objected. 'I'll swim out.'
'I will too,' said Biff.
The two plunged into the water and struck out for the stricken man.
Meanwhile, Frank and Chet sped up the slope, cut across a strip of grass, and began running down the
embankment toward the rowboat.
