noon
We were approaching another range of mountains at the time , and when we reached them , instead of winding across them through some high-flung pass we entered a mighty natural tunnel -- a series of labyrinthine grottoes , dark as Erebus . The guards had no torches or light of any description . In fact we had seen no artificial light or sign of fire since we had entered Pellucidar . In a land of perpetual noon there is no need of light above ground , yet I marveled that they had no means of lighting their way through these dark , subterranean passages . So we crept along at a snail 's pace , with much stumbling and falling -- the guards keeping up a singsong chant ahead of us , interspersed with certain high notes which I found always indicated rough places and turns . Halts were now more frequent , but I did not wish to speak to Dian until I could see from the expression of her face how she was receiving my apologies . At last a faint glow ahead forewarned us of the end of the tunnel , for which I for one was devoutly thankful .