Suddenly his eager gaze was shifted to a new quarter.  He stared, wide-eyed and breathless.

Out of the night, running like mad along the shore and across the acres of sand and clay and mud, came a body of men armed with rifles.  They were making directly toward the scene of conflict as fast as they could find their difficult way.

“Who are they?  Where have they come from?” Billy wondered.

And then, like a flash, he understood.  “Oh!” he gasped.  “Oh, I know, I know now!  They’re the men from the Petrel!  Marines, I guess—–­if that’s what you call ’em.”

It was true; the new arrivals were the Revenue Service men, and as it chanced, they had come just in the nick of time.  For Joe Durgan, Branks, Harry Mole, Max, the villainous half-breed, and others at the huts, were being reinforced by Bego’s followers who had hurried up from the bonfire; and they were beating back the soldiers, whom they now outnumbered.

Suddenly Billy heard another yell, a wild, eerie, shrill call, and Dave, leading Norton and the Boy Scouts, sprang from their boat which had crept up to the farther side of the clearing, and dashed forward to meet the crew of the Petrel.

Recognizing them even in the darkness—–­which now began to be relieved by stray gleams of moonlight struggling out of the clouds—–­the revenue men turned to the left under Dave’s guidance, and took a short-cut, coming up in the rear of the battle.

Alone on the little mound, Billy realized that he was separated from his reunited scout friends and their allies by a small mob of desperately fighting men.  He was cut off from the rest by reason of Dave’s having steered the boat along a watercourse of which he, Billy, knew nothing; in fact, he had lost his bearings and knew not in which direction the improvised camp lay.

However, the conflict before him absorbed his thoughts and left him no time to worry about his own predicament.  He was still wondering how the revenue men had happened to arrive at a critical time.

The explanation was as follows: 

Unknown to Billy or to any of his friends, the Petrel had steamed full speed to Palmetto Key; and Captain Vinton, sighting the cutter from the deck of the concealed Arrow, had signaled to her captain, telling him just where to land his men.  This accounted for their unexpected arrival, which soon turned the tide of battle in their favor.

Creeping forward, Billy saw the smugglers fleeing in all directions, after setting fire to the two smaller cabins.  As they ran, they exchanged shots with the soldiers and the revenue men; but, owing to the gloom, these shots failed to take much effect, beyond slightly wounding their captors.  Fired on in turn, they ran toward the beach, past their smouldering bonfire, near which their boat was drawn up on the sands waiting to take them back to the Esperanza.