In the Camp of the Black Rider

Ted's guess was a perfectly correct one. Before they were half down the mountain side the rain began to come down in sheets.

Added to the rush of wind and water there was the bewildering addition of thunder and lightning. The thunder kept up the rolling roar as the sound bounded from mountain slope to mountain slope, and the flashes of lightning almost blinded them. The quality of it was deceptive. It revealed obstacles in the path which were imaginary most of the time, and by constant flashing made the lanterns of little or no use. Two of them had already been puffed out by the wind and the rain drops on the others caused them to sputter and hiss. It was with a sense of feeling rather than seeing their way that the boys pushed on.