The Glass Mountain (pulp)

An Idaho railroad project tunnels through Mount Rainod (a black basalt "Glass Mountain").

An elderly Pawnee scares workers with tales of a rain god in the mountain.

Rrevived by Benson after being electrocuted, Josh is left realistically thoughtful; he describes death as like being unconscious.

The villain learned that the mountain is hollow; he can build a tunnel at a fraction of the projected cost, pocketing the difference.

The tunnel is flooded deliberately from an underground stream to stop work and kill Benson and his team; typically, this planned death trap destroys the criminals.