“I can’t see a thing, but whatever has come must be in our rear. Shall we go out?”
“We’ve got to learn what it is.”
“I think some animal has swum up from the sea. At all events, we’ll soon know. Don’t make the slightest noise as you follow me.”
Then very cautiously Ned crept out until he had a full view of the shores and as far back in the interior as the center of the island.
There was not so much as a bird to be seen, and what seemed very strange, the groan was not repeated, although they listened intently fully five minutes.
Then he rose to his feet and his companions did the same.
The most perfect silence reigned save for the soft lip, lip, lipping of the water on the sandy shore.
“Well, that beats me!” Ned said aloud after ten minutes had passed and nothing was heard. “It can’t be that all three of us have been dreaming.”
“There was more than a dream in that terrible noise,” Vance replied with a shudder.
Ned led the way completely around the tents and then to the edge of the grove without having discovered anything.