“Well, the hole’s made through the solid rock,” said Mike. “It will have to burst the rock!”
Even as they spoke, a frightening thing happened. The water falling from the roof seemed suddenly to become bigger in volume and noise — and the boys saw a great mass of rock fall slowly from the roof! As Jack had said, the hole was no longer big enough to take the rush of water, and the force of its rush had burst away part of the solid, rocky roof!
Water at once flowed over the floor of the cave, almost to the feet of the astonished boys. They leapt up at once, staring at the water falling from the roof at the other end of the cave.
“I say! I hope the whole roof doesn’t give way!” said Jack. “There must be a terrific rush of water to burst through the rock like that.”
Nothing more happened, except that the extra volume of water made more noise and flooded the floor of the cave almost up to where the boys stood.
“Well, anyway, we’re safe,” said Mike. “We are just at the opening of the passage that leads upwards to the other cave. The water comes from the other direction. If it gets deep in here we’ll have to go up the passage, that’s all, away from it.”
It got no deeper, however, so the boys waited patiently. Twenty miriutes went by, and there was no sign of the return of Ranni or Pilescu. Mike began to feel worried.
“I wish they’d come back,” he said. “I feel as if I can’t stay here doing nothing much longer!”
“Whatever are Ranni and Pilescu doing?” said Jack, impatiently. “They must be right out on the mountainside by now!”
“Let’s go up the passage and find out,” said Paul, at last. “I simply can’t sit here any longer.”