Even before Captain Tom turned he heard the sudden throb of the twin screws of the propellers, and felt the speed being reversed.  That told him, instantly, that Joe had found some reason for stopping the “Restless” in a hurry.

As the young commander bounded forward the steady ray of his own searchlight showed him that the seventy-footer had also stopped her headway.

Hank was still at the wheel, but young Dawson was beside him on the bridge deck.

“There they go ­dropping their anchor overboard,” cried Joe, pointing.  “The water’s shallow along this coast, of course.”

“We’ll move right in, between that boat and the shore, and drop anchor, too,” decided Captain Halstead, taking the wheel and reaching for the engine control.  He sent the “Restless” slowly forward into place, then shut off headway, ordering: 

“Joe, you and Hank get our anchor over.  Dalton can’t get anything or anybody ashore, now, without our knowing it.”

“But what can his plan be, anchoring on an open coast?” demanded young Dawson, as he came back from heaving the anchor.

“Our job is just to wait and see,” laughed Captain Halstead.

Mr. Seaton came on deck again, to learn what this sudden stopping of the boat meant.

“It’s some trick, and all we can do is to watch it, sir,” reported the young skipper of the “Restless,” pointing to the anchored Drab.  “Yet I think the whole situation, sir, points to the necessity for your taking my recent advice and acting on it without the loss of an hour.”

“Either the registered mail, or yourself as a special messenger,” whispered Seaton, hoarsely, in the boy’s ear.  “Yes, yes!  I’ll fly at the work.”

“Don’t hurry back below, though,” advised Halstead.  “Stroll along, as though you were going below for a nap.  A night glass on the seventy-footer is undoubtedly watching all our movements.”

As the two boats swung idly at anchor, on that smooth sea, their bows lay some three hundred yards apart.  The night air was so still, and voices carried so far, that those on the deck of the “Restless” were obliged to speak very quietly.

Over on the seventy-footer but one human being showed himself to the watchers on the smaller boat.  This solitary individual paced the drab boat’s bridge deck, puffing at a short-stemmed pipe.

“I’d give a lot to be smart enough to guess what their game is,” whispered Joe, curiously.

“It’s a puzzle,” sighed Captain Tom Halstead.  “It looks, now, as though Dalton and Lemly are trying to hold us here while someone else does something on shore.”

“Then you think the two who landed on either bank of the river ­”

“We know that neither of them was Dalton or Lemly, but I’m beginning to suspect that one, or both, of those fellows carried messages, somewhere and of some nature.  In that case, we’re letting our curiosity hold us up here while the enemy are accomplishing something at some other point.”

“Confound ’em!” growled Joe, prodding the bulwarks with his toe.  “They’re clever rascals!”

“Meanwhile,” whispered Tom, “I’ve just been thinking of something else that we ought to be doing.”

“What?”

“There may be another steamship for Rio Janeiro passing somewhere in these waters at any time.  We ought to send out a call on the wireless at least once an hour.  There’s something else in the wind, old fellow, and we do want to know when the first steam vessel for Rio passes through these waters.”

“Then I’ll go below and get at work at the sending key,” proposed Dawson.  “Send out the wireless call once an hour, you say?”

“Yes; yet we don’t want to forget that we’re being watched all the time from that old drab pirate yonder.  Don’t let the enemy see you going to the cabin.”

“I’ll drop down into the motor room and use the passageway through.”

Dawson was gone ten minutes.  When he returned he shook his head, then stood looking out over the sea.  Excepting the “Restless” and the drab seventy-footer there was no craft in sight.  Not so much as a lighthouse shed its beams over the ocean at this point of the coast.

“Say, it’s weird, isn’t it?” muttered Joe Dawson.  “We can’t see a thing but ourselves, yet down in the cabin I’ve just been chatting with the Savannah boat, the New Orleans boat, two Boston fruit steamers, the southbound Havana liner and a British warship.  Look out there.  Where are they?  Yet all are within reach of my electric wave!”

“There are no longer any pathless roads of the sea ­not since the wireless came in,” declared Tom Halstead.  “If there were enough vessels to relay us we could talk direct with London now.  The next thing will be a telephone in every stateroom, with a wireless central on the saloon deck or the spar deck.  But gracious!  We’ve been forgetting all about our poor prisoner in the starboard stateroom.  He must have a royal case of hunger by now.  Tell Hank to take him in some food and to feed the poor fellow, since he can’t use his own hands.”

Later time began to drag by.  There were few signs of life aboard the seventy-footer.  Sending Joe and Hepton down to the motor room berths as watch below, Tom kept Hank on deck with him.  Bye-and-bye Joe and Hepton took their trick on deck, while Halstead and Hank Butts went below for some sleep.  Through most of the night Powell Seaton remained hard at work over his writing, often pausing to read and make some corrections.

Morning found the two boats still at anchor.  With sunrise came a stiffer wind that rocked the “Restless” a good deal.

“Now, look out for one of the sudden September gales,” warned Captain Tom Halstead, as, after the second short sleep of the night, he came up on deck, yawning and stretching.  He stepped over to read the barometer, then turned quickly to Joe.

“Looks like something’s going to happen, doesn’t it?” queried Dawson.

“Yes; there’s a disturbance heading this way,” admitted Tom, looking around at the sky.  “Yet it may be hours, or a day, off yet.  If we were going under canvas, though, I’d shorten it.”

“The captain of the Drab evidently believes in being prepared,” hinted Joe, nodding in the direction of the other craft.  Two men were now visible on the deck of the seventy-footer.  They were taking up anchor, though not doing it with either speed or stealth.

“I reckon we have to take our sailing orders from them,” nodded the young skipper.  “You’d better get the motors on the mote, Joe.  I’ll have Hank and Hepton help me up with our anchor.”

Soon afterwards the Drab was heading north at a ten-mile gait; half a minute later the “Restless” started in leisurely pursuit.

After half an hour or so the Drab headed into another open roadstead, anchoring a quarter of a mile from shore.  Tom dropped anchor some three hundred yards to the southward.

“Keep your eye seaward, Hank,” directed the young skipper.  “Joe, if you’ll see whether Mr. Seaton wants anything, Hepton and I will keep a keen eye on the shore.”

“Mr. Seaton is asleep in the port stateroom,” Dawson reported back a moment later.  “I’ve made eight calls through the night, but I’ll get at the sending key again, and see whether there’s anything in our line within hail.”

Hardly had Joe Dawson vanished below when Skipper Tom uttered a sudden exclamation.  A sharp, bright glint of light from under the trees on shore caught his watchful eye.

“Look there!” the young captain called, pointing to the flash.

“There’s another,” muttered Hank Butts, pointing further up the coast.

“By Jimminy, there’s a third,” cried Hepton, pointing.

“Signals for the Dalton-Lemly crew,” uttered Tom, disgustedly. “They are getting news, now, and of a kind we can’t read.  Hank!  Call Mr. Seaton. He ought to be on deck, watching this.”

The charter-man was speedily up into the open.

In the meantime Joe, at the powerful sending apparatus below, sent the spark leaping across the spark-gap, and, dashing up the aerials, there shot into space the electric waves intended to be gathered in by any other wireless operator within fifty or sixty miles.

Crash-sh!  Ass-ss-ssh! hissed the spark, bounding, leaping to its work like a thing of almost animal life.

Bang!  This last note that came on the air was sharp, clear, though not loud.  Whew-ew!  A bullet uttered a swift sigh as it sped past the signaling mast twenty feet over the heads of the watchers of the “Restless.”

“Confound it!  Rascals on shore are shooting at us,” exclaimed Powell Seaton, turning swiftly to peer at the forest-clad shore line.

“No; they’re shooting at our aerials!” retorted Captain Tom Halstead.

Bang!  Whe-ew-ew!  Clash!  Then there was a metallic clash, for the second rifle shot from the land had scored a fair bull’s-eye among the clustered aerial wires.  There was a rattle, and some of the severed wire ends hung down.

With an ugly grunt, Hepton bounded down into the motor room, passing up the two rifles.

“We must be careful, though,” warned Mr. Seaton.  “This time they’re not shooting at us.”

“Load and be ready, though!” uttered Captain Tom, dryly.  “They soon will be shooting at us.”

Several more shots clattered out, and two more of the bullets did further damage among the aerial wires.  Then Joe came dancing up on deck, his eyes full of ire.

“The infernal scoundrels have put our spark out of business,” he cried, disgustedly.  “We haven’t wire enough left to send five miles.  Where do the shots come from?”

“From the shore,” Halstead replied, “but see for yourself if you can locate the marksmen.  We can’t.  They’re using smokeless powder, and are hidden so far in under the trees that we can’t even make out the flashes.”

“It’s out of my line to locate them,” announced Joe Dawson, with vigor.  “It’s mine to see that the aerials are put on a working basis again.”

He vanished, briefly, into the motor room, soon reappearing with a coil of wire and miscellaneous tools.

“Good!” commended Halstead, joyously.  “Mr. Seaton, we have wire enough to repair a dozen smashes, if need be.  On up with you, Joe.  I’m at your heels.”

Joe started to climb the mast, using the slightly projecting footholds placed there for that purpose.  Tom let him get a clear lead, then started up after his chum.

From the shore broke out a rapid, intermittent volley.  Steel-clad bullets sang a song full of menace about that signal mast.

“Come down, boys!  You’ll be killed!” roared Mr. Seaton, looking up apprehensively.

While Joe kept on climbing, in silence, Skipper Tom looked down with a cool grin.

“Killed?” he repeated.  “Well, if we’re not, we’ll fix the aerials.  We can’t allow strangers to put us out of business!”

Joe found his place to go to work.  Tom halted, with his head on a level with his chum’s knees.  From the shore there came another burst of rifle-fire, and the air about them was sternly melodious with the pest-laden hum of bullets.  Two of the missiles glancingly struck wires just above Dawson’s head.

In the lull that followed Joe’s voice was heard: 

“Hold the wire, Tom.  Pass me the pliers.”