The Squeaking Goblin (Doc Savage, #35)

The tale of a skeletal sharpshooter who used a strange squeaking weapon was told around the backwoods campfires. To most it was just a legend, but for some it became a terrifying reality - especially those whose skulls were shattered by the deadly "disappearing bullet." Doc Savage dodges flying death as he tracks the spectral killer who defies every law of nature!