Mysterious, dark, out of the unknown deep comes a new satellite to lure three courageous Earthlings on to strange adventures.

Chet Ballard answers the pinpoint of light that from the craggy desolation of the moon stabs out man's old call for help.

A science fiction novel that was originally produced in four parts in the publication: Astounding Stories in June, September, November 1932, January 1933. The main character is Dean Rawson, who plans on discovering a way of mining power from a dead volcano, but ends up discovering more than he bargained for.