"Very well. Light your lantern, and I'll get a fountain pen and a blank check."
They got upon their feet.
While the negro was procuring the light, Mason got his check, and they crossed the cavern, entered a narrow fissure in the wall, and vanished.
The detectives glided from their place of concealment.
Every word uttered had been heard by them.
They entered the fissure.
Some distance ahead was the light.
It suddenly disappeared around a bend, and the officers observed, its dim rays illuminating a small chamber, as black as midnight.
Reaching the end of the passage, the Bradys glanced through the big opening and saw a small cavern of the same crystal formation as the two other caves, excepting that everything here was black and dark brown from some chemical discoloration.
It was a gloomy place.