Meanwhile the girls, guided by the lights ahead and aided by the two lights behind, which were directed helpfully along their path, made their way laboriously down the slope and along the many-angled gallery to the opening at the other side of Holly Hill, as the high, rounded elevation on and around which the city was built was called. Under different circumstances undoubtedly they would have been much interested in this experience as a subterranean exploration. And they had all the time they might need for such exploration, for the dusk of evening had not yet developed into darkness and they had to wait in the mine over an hour before it was deemed safe to venture out with the captives.