Captain Bego, of the Esperanza, however, knew that the Petrel was on his trail, and he was all the more anxious to make “a getaway with the goods.”

The bonfire, instead of dying down at last, seemed to rise higher and higher, casting a lurid glow over the marshes and streams, and even upon the dark waters of the ocean.  Made of driftwood, bundles of dried saw-grass and withered cypress boughs—–­industriously piled on by Max, the half-breed, who had been sent there for that very purpose—–­it blazed merrily, and a shower of sparks swirled around it, veering toward the cabins.  To all appearances, the three cabins seemed doomed to take fire; in which case nothing could save them or their contents.

The soldiers from the fort and Dave had disappeared into the darkness of the deeper shadows.

Eager to see the fire and to find out what was going on in that vicinity, Billy, Alec, and Roy Norton crept forth from their hiding place and approached the glowing beacon.

For the most part, they followed the bank of a creek or inlet which, like all its fellows, wound and zig-zagged through the springy turf of the marsh.  This particular waterway reflected the glow of the bonfire more brightly than the others, from which fact they deduced that it would be the most direct path.

On getting nearer, the hum of human voices showed them that a number of men had assembled, some of whom were engaged in throwing water over the blaze, others in patrolling the beach.  Evidently the bonfire was burning too high and casting too much light to suit their purposes.

“Who are they?” queried Alec in a whisper.

“I don’t know,” answered Norton as quietly.

“Look!” Billy exclaimed softly.  “There are three mulattoes in that bunch over by the dune.  And see that tall, skinny, dark man with the oilskin coat over his left arm?  That must be Captain Bego.”

“He certainly looks like Vinton’s descriptions,” Norton observed.

“And he’s giving orders as if he-----”

“Hark!  What’s that noise?”

Breathlessly they waited and listened.

After another full minute they again heard the sound—–­a low rumbling, like distant thunder.

“Gee! it sounds dangerous,” said Billy.

“I wish we knew what it was.”

“I can make a pretty good guess,” Norton added, still whispering. 
“It’s a-----”

In the middle of his sentence he was interrupted by a shout from one of the mulattos.

“Boat!  Boat comin’!” cried the man, running toward the others, who by this time had almost extinguished the bonfire.  His announcement was distinctly heard by the three hidden scouts.

“Wonder if he has seen our captured launch or a boat out at sea?” said Alec.

“Boys, he means—–­the Petrel!”

“Oh!” the other two exclaimed dubiously.

“How do you know?” demanded Billy.  “How can you tell?”