All the camp was fast asleep and silence reigned unbroken, except for the exhaust of the machine and the occasional heavy fall of a fire-eaten tree in the jungle. But in their loneliness the boys were comforted by the knowledge that in their tents Captain, Chris, the engineers, and many of the Spaniards were sleeping, fully dressed with their guns by their sides, ready to run to the lads' assistance at the first alarm. And soon it came, the sharp crack of rifles around both camp and machine. The two lads answered promptly, firing at the bright streaks of the blazing rifles in the darkness. "Keep down, keep down. Get behind the sand heaps," Charley shouted, as those in the tents came running to their assistance. "Keep down. They are shooting to kill this time." A rain of bullets thudded against the sand heaps as the defenders dropped behind them and fired over the tops. The darkness was pierced with streaks of spurting fire as rifle spoke to rifle. It was evident that the enemy were shooting to kill, and the defenders did the same. Wherever a rifle flash lit up the darkness they aimed at the place and quickly fired. Occasional cries and oaths told them that some of their bullets were finding their mark. But they were not to go unhurt for their part. Charley, who had raised himself up to fire, felt the thud of a bullet and his left arm dropped helplessly by his side. In the excitement he felt no pain, but, letting go his rifle, he drew his automatic and blazed away with it. Walter, behind the next pile, had his straw hat shot off his head. Bob Bratton pitched forward on his face and lay still and motionless, while one of the Spaniards sank to the ground, his hand clapped to a wounded leg and cursed fluently. Once Walter glanced back at the machine. Its platform was revolving rapidly and the rifles of its crew were spatting viciously. But the enemy did not now have the protection of the trees, and they could not long face the hail of lead being poured upon them. Their firing suddenly ceased. From where they had stood came piercing shrieks, and following the shrieks came frightened yells and the thud of running feet. "Captain, take most of the men and go to the aid of the machine," Charley commanded. "The fighting is over here." The old sailor hurried away, followed by McCarty and most of the Spaniards. From the darkness ahead of the two boys still came the awful shrieks. "Chris, get a lantern, we must find out what's the matter out there," Charley said.