Meanwhile those who had swarmed aboard the boat which they had been so feverishly following were at a loss to understand what had happened.
The sailor had quickly discovered that he had made an error in firing at the mast, and as by then he was within sight of the stern, he came to a sudden halt, and sheltered his body behind the big mass of timber.
"Shoot when you see them," he shouted. "They must be lying on the deck. Give them a volley, comrades."
It was one of the gauchos who made the gang aware of the fact that the stern was empty. He peered into the darkness for a moment, and then rushed aft till he came to the rail, his revolver held in readiness in case his eyes should have deceived him.
"Not here!" he called angrily. "This is where we saw them when the last shot was fired. They must have gone forward, or have dived into the cabin. After them! We will riddle them with bullets once we come upon them. Ah, peste take the man who fired then! Be careful with your weapons."
He turned savagely upon one of the gang, who, thinking he saw a figure beside the rail a little for'ard of the stern drew trigger on it, sending a bullet dangerously near his comrade. Then, joining the sailor, this gaucho led the way forward, this time at a slower pace, searching every foot of the deck.
"Empty!" exclaimed the sailor with an oath. "Then they have gone into the cabin, and we shall have a pretty business to get them out. What's best to be done?"
He turned on those who followed him, forgetful of the fact that none knew English. But they seemed to guess at his meaning, for the gaucho promptly led the way back to the cabin.
"An ugly place to search," he admitted as he made out the outline of the roof of the saloon which Dudley and Mr. Blunt had occupied, and came to a halt at the short flight of stairs leading down to it. "A man does not care to dive into a dark hole like that and be shot down like a dog. The fellows are skulking behind the door, and will see us before we can catch sight of them. What's to be done? Coop them up below and wait till morning seems the best way out of the difficulty."
"And have a hundred busybodies asking what the noise is about, and why we are so carefully shooting white men on the river," shouted the man at his elbow, pushing him aside indignantly. "What has to be done must be done now. I'm going into the cabin."