human
I have the secret! he whispered, and placed his ear to the ground. The Baron imitated him. True enough the singing was _below_. They caught other voices now. Lecour pondered a few moments. He followed an irregular rent in the rock and disappeared to one side. Returning on tiptoe, excited for the first time, he beckoned Grancey to accompany him and led the way with the greatest precaution to a long crack in the side of a hill, scarcely discernible without the closest scrutiny, through which the accents came quite audibly, and they caught sight of the objects below in a grey light. They made out a narrow, oblique cavern, formed by the widening of what geologists call a