They had been saving the fast-waning current in the electric lamps against the time of need. They might have but little further use for it, so both Andy and his brother pressed the springs that turned on the gleaming lights.
In the glow they could see the black and gurgling water at their knees. It was swirling around from the force of the tide outside that was rushing into the cave. Though the stone thrown down by the man at the entrance prevented our heroes from escaping, the bowlder did not fit so tightly but what water could come in.
"Now to see what's back of us," spoke Frank, turning around as well as he could on the small shelf, and flashing his light on the wall behind him.
"Say!" suddenly exclaimed Andy, "doesn't it strike you that the water isn't coming in so fast is it was?"
Frank held his light lower, and looked at the rising tide.
"There doesn't seem to be quite so much force to it," admitted the elder Racer lad, "but I'm afraid that's only because it's higher, and because it has to wind in and out of so many passages, and force itself under and around the rock which that scoundrel threw down. I wish we had him here!"
"I guess he's far enough off by this time," remarked Andy. "But let's see if there's a way to get higher up."
Together they examined the wall of the cave against which they had been leaning. Frank uttered a cry of joy.
"It's mostly dirt, not stone!" he exclaimed. "We can cut steps in it, and climb up. Maybe we can get high enough so that the tide won't reach us, or at least we can keep our heads above water until it goes down. Come on, where's your knife?"
Working by turns, with the only knife available between them, the boys began frantically cutting niches or steps in the dirt wall. Fortunately it was packed hard enough so that it did not crumble. They took turns at the desperate labor, one holding the torch, and the other wielding the knife.