The mouth was overgrown with hazel-bushes and brambles and long, trailing twines of ivy, and it seemed to the children as if no foot but theirs had disturbed it for a long time. Peggy looked at Bobby, and Bobby looked at Peggy, and I think each felt just a little inclined to hang back, though neither would have confessed it for worlds; then, with the solemn air of a Guy Fawkes, Peggy lighted the lantern, and boldly plunged into the darkness, with Bobby following particularly closely at her elbow. At first the entrance was rather narrow and low, but it soon broadened out until the roof was ten feet or more above their heads. The sides of the rocky walls bulged out into irregular shelves, covered in parts with moss, and moist and clammy with slowly-dripping water.