Had not Mr. Damon pulled Tom to one side, there might have been a different ending to this story.  As it was the weapon hissed through the air over the head of the young inventor.  The next minute his revolver spat lead and fire, but whether he hit any one or not he could not see, as the place was so filled with smoke, from the powder and from the torches.  But some one yelled in pain.

“Crouch down and fire!” ordered Tom.  “Low down and they’ll throw over our heads.”  It was done on the instant, and the four revolvers rang out together.

There were howls of pain and terror and above them could be heard the gutteral tones of Delazes, while Andy Foger yelled: 

“Look out dad!  Here, help me to get behind something or I may be hit.  Mr. Delazes, can’t you tell those savages to throw spears at Tom Swift and his gang?”

“They are doing it, Senor Foger,” replied the Mexican.  “Oh, why did I not think to bring my gun!  We haven’t one among us.”  Then he called some command to the head-hunters who had apparently been enlisted on the side of himself and the two Fogers.

The automatic revolvers were soon emptied, and the place was now so full of smoke that neither party could see the other.  The torches burned with a red glare.

“Reload!” ordered Tom, “and we’ll make a rush for it!  We can’t keep this up long!”

It took but an instant to slip in another lot of cartridges and then, on Tom’s advice, they slipped the catches to make the automatic weapons simple ones, to be fired at will.

They sent several more shots through the door-way but no cries of pain followed, and it was evident that their enemies had stepped back out of the line of fire.

“Now’s our chance!” cried Tom.  “The way is clear.  Come on!”

He and the others dashed forward, Tom carrying the golden head, though it was hard work.  It was not very heavy but it was awkward.

As they rushed through the now open gateway they crouched low to avoid the spears, but, as it was one grazed Tom’s shoulder, and Eradicate was pierced in the fleshy part of his arm.

“Forward!  Forward!” cried Tom.  “Come on!”

And on they went, through the smoke and darkness, Ned flashing his electric torch which gave only a feeble glow as the battery was almost exhausted.  On and on!  Now they were through the stone gateway, now out in the long tunnel.

Behind them they could hear feet running, and several spears clattered to the stone floor.  Lights flickered behind them.

“If only the river bed is dry!” gasped Tom.  “We may yet escape.  But if they’ve filled the channel—­”

He did not dare think of what that would mean as he ran on, turning occasionally to fire, for he and the others had again reloaded their revolvers.

CHAPTER XXV

THE ESCAPE—­CONCLUSION

The noise behind our friends increased.  There were shouts of rage, yells of anger at the escape of the prey.  High above the other voices were the shrill war-cries of the head-hunters—­the savages with their grewsome desires.