"No-o; Dave watch, saw steamer,—-no more sleep, no forty winks."

"Oh, come!" laughed Billy. "I heard you snoring, Dave; you woke me up! I thought it was thunder!"

"Nothing less than thunder or a cannon firecracker would wake you up, Billy,—-as a general rule," said Hugh, flinging one arm over his chum's shoulders and giving him a vigorous hug.

"Look yonder, boys!" shouted Captain Vinton at the helm. He pointed aft, and the four lads sprang to their feet and hurried toward him, alert and eager for a new surprise.

Some distance behind them, toward the mainland, a thin trail of smoke which had not been seen for two or three hours was now visible inside the keys. Could there be any reason for the reappearance of that smoky blur against the sky? Was it made by the mysterious steamer? If so, was she following the Arrow?

"By the shades o' shad, I orter know that boat!" exclaimed Vinton in puzzled chagrin. "See? She's coaled up, goin' for all she's worth. Alec, git out my glass from the cabin, take a look, and see if there's many men aboard."

Alec ran to do the captain's bidding. Descending into the cabin, he took from a locker an old-style marine telescope with which he hurriedly returned to the deck. After some focusing he managed to catch a glimpse of the steamcraft, just before she partially disappeared from sight behind one of the sandy reefs that fence off the sound.

"The crew of the steamer seem to be quite excited," Alec said, as he trained the telescope upon them. "I can see sailors running across her deck, and two of them have just hoisted an American flag. Some others are waving signals and—-"

"What?" shouted the captain. "American flag, did you say?"

"Yes. What do you think of that?"

"Reckon she wants to speak us."

"Why?" asked Chester.

"Looks like this is the first time she's seen us," said Vinton, taking the marine glass from Alec. "But it can't be the same craft we sighted back yonder, last night. Anyhow, if they're wavin' signal flags,—-and they are, sure enough!—-they must want to speak the Arrow. That's plain. I'm goin' to ease in more and see who's aboard. Look! the dinged old boat is comin' out from behind the bar now."

Pondering some contingency which he did not explain to the boys, Vinton shifted the helm; and his sloop, hitherto heading in a southwesterly direction, now began to edge closer to the line of keys. Had Vinton not known his course so thoroughly from long experience in sailing these channels, inlets, and lagoons, it would have been dangerous; but he dexterously eluded the various reefs and oyster bars and brought the Arrow safely into smoother water. Meanwhile, the boys noticed that the wind, which had blown so strongly, was beginning to slacken, thus allowing the steamer to gain on the Arrow quite perceptibly. They saw then that she was a small steamer, like a steam yacht, and light gray in color,—-perhaps one of the United States revenue cutters.

Captain Vinton was astonished. He had already begun to have serious doubts that this could be the same mysterious vessel he had seen cruising about the islands the night before. All at once, unexpectedly, his doubts were resolved into a certainty that it was not the same, for even while he was wondering, a strange thing happened:

A long, low, gray shape, something like a built-for-speed tug-boat with a short funnel, darted into view from between two keys, and, crossing the wake of the revenue cutter, glided swiftly along the very course the Arrow had taken, heading back toward Snipe Point. Before the sloop and the steamer had come within hailing distance of each other, the strange craft, not depending on the dying easterly wind, was well along the course, sending back—-toward a trail of darker smoke.

CHAPTER II

A CONTRABAND CARGO

"Well, what d'you know about that?" queried Billy, easily relapsing into slang when the first few minutes' surprise had worn off.

"Dunno much about it," Captain Vinton answered in a somewhat gruff tone, "but it looks to me mighty like a filibuster's craft, or p'rhaps a smuggler's."

At the word "filibuster," the boys—-figuratively speaking—-pricked up their ears.

"What on earth can they be trying to smuggle?" was Hugh's eager question, to which the captain replied promptly:

"Arms,—-leastways, cartridges or gunpowder. They ain't tryin' to smuggle 'em into Fluridy, but out of it," he explained. "Some gang of raskils is buyin' small quantities of war goods up state—-or else from Cuby—-totin' 'em down the coast an' through th' Everglades, and gettin' 'em aboard some steamboat like that one, and so away where they'll do the most harm. Get me?"

"Yes," replied Alec, "but I never would have thought such tricks were possible in these days."

"Boy, you can't never tell what's just possible or what ain't, in these days," gravely asserted Captain Vinton. "All sorts o' things is like to happen, and sometimes it's durned hard to know just what's goin' on. But if that's any filibustin' outfit, they'd better make tracks out o' these waters as fast as they can lay beam to wind'ard."

So saying, he shifted the helm again and bore away at an angle that would enable them to come close to the revenue cutter, now scarcely a quarter of a mile astern. Lighter and lighter came the wind, slower glided the Arrow over the long heavy swells, nearer and nearer came the cutter, going at a steady, rapid rate. Soon the two vessels were within hailing distance, and a megaphone call came across the water, clear and distinct:

"Sloop, ahoy! Can you understand?"

"Aye, aye!" called Vinton.

The five boys gathered around him, eager to hear the interchange of calls. Even Dave rose and shambled over to the little group at the tiller. On the other vessel they could now see a number of men in blue uniforms and one in a civilian's suit of gray tweeds.

"Who've you got aboard?" came the next question from the captain of the Petrel.

Vinton briefly stated his passenger list and explained the purpose of their cruise.

"Bound for Key West now?" shouted the Petrel's captain, whom
Vinton, studying him through the marine glass, recognized as James
Kelsey. "Trying to dodge that craft that just passed us, or trying
to catch her?"

"We were goin' to report as how we seen her las' night off Snipe Point," bawled Vinton, speaking through a megaphone which Dave had handed to him. "Thought you fellows were at Key West."

"We were until this morning," came the answer. "We've been chasing that boat. She's the Esperanza, a smuggler. Have you seen her throwing anything overboard, or picking up stuff—-like boxes or small kegs?"

Then a light of understanding broke upon Vinton's mind. So that was what the smuggler had been doing all night! Not grappling for the cable, but stealthily picking up a contraband cargo of munitions of war, small stores such as could be cast adrift along the coast in some prearranged method and gathered in by those who had been instructed to recognize the floating objects! What were they? Water-tight kegs of dynamite, submerged, but buoyed up by thrice their weight of corks? Boxes of rifle bullets? Or merely harmless glass bottles containing, perhaps, written descriptions of the country to be invaded, photographs of fortifications, details of naval or