As the machine drove up toward the mouth of the cave, the boys were startled at seeing two rough looking men emerge from the entrance and slink away to the south, half hidden by the unevenness of the ground and the thick shrubbery. Their hurried movements and evident desire to avoid meeting the boys marked them as suspicious characters. Fearing that they might have committed some malicious act to render the place uninhabitable, Ernie hastened toward the cave, followed by the other boys, to make an inspection.