The three of them decided it was not safe to go back to the open area tonight. After waiting a while longer still in the dark to see that their attacker was not coming, they searched the gloom around for a place to spend the rest of the night.  
Randy found an opening in the dense underbrush ahead of them. Jill and Ted followed him and his flashlight beam along the trail. Suddenly they saw him stop dead in his tracks. Ted walked abreast of him.
 
“What do you see?” Ted asked.
 
226
Randy did not reply but instead shot his light ahead into the darkness. Ted saw before them a huge cave entrance.
 
“Gosh, do you suppose that’s the den of some wild animal?” Ted asked.
 
“I don’t know,” Randy answered in a quivery voice. “It seems like a good place to stay if it isn’t.”
 
Jill had joined them by now. She too had taken some of the load of the spare oxygen cartridges.
 
“Are we going into that spooky place?” Jill asked.
 
“We can go up to it carefully and shine our light in,” Ted said. “But we’d better be ready to run if something comes charging out! I wish I had that gun now!”
 
Jill hung back as Randy and Ted moved stealthily forward toward the black cavern entrance. Randy had his light shining directly into it all the time they were moving. When they were at the threshold of the cave, they got a good view of the interior.
 
“It’s not deep at all!” Ted said. “It just goes back a little way.”
 
227
“It looks deserted too,” Randy added. “Seems safe to me. What do you think, Ted?”
 
“Let’s go inside and see if there’s anything lying around,” Ted suggested. “If it’s a den, there ought to be bones and things.”
 
Cautiously they entered the cavern. Its ceiling reached high over their heads and the opening was festooned with trailing vines and creepers. Even the jungle growth seemed to have taken over, weeds and thick grass choking the floor. Boulders of all sizes were scattered around.
 
“It looks like it hasn’t been used for years and years,” Ted commented.
 
They flashed the light over the whole interior, but there was no sign of recent use. There was one other exit—a narrow passage at the rear.
 
“If we close up that rear opening with a big stone, it ought to be safe for us to stay here,” Randy said.
 
Ted agreed with him. They called Jill, and the three shoved a large red boulder in front of the narrow passage. They divided watches again, but before relaxing for the night, they replaced their air cartridges with new ones.
 
228
Randy took first watch this time. Ted was very tired from their exhausting race and had trouble falling asleep, but the next thing he knew, Randy was shaking him to change watch.
 
The rest of the night passed without further disturbance. The boys got softhearted about calling on Jill for her turn, and rather than wake her, they stood her duty. Another change of air cylinders had to be made before morning. Ted was able to change Jill’s while she slept.
 
The orange glow of dawn was a welcome sight to the children. Things did not seem half so grim in the dawn as they had the night before. The sun’s feeble rays shone directly into the cave mouth. The boulder covering the rear opening was still in place.
 
Ted caught Randy’s eyes staring thoughtfully at the boulder. He wondered if Randy was thinking the same thing that he was: What was on the other side of that mysterious opening?
 
“Hadn’t we better be getting back to the open place?” Jill asked, as they were putting on fresh air tanks again.
 
229
“The search party won’t be coming until a few hours yet,” Randy said. “Besides, it’s not very far.”
 
Ted knew then that Randy, too, was curious about the opening. He was stalling their return.
 
Ted then came rig............