Steranko paintings graced the covers of this Shadow massmarket paperback series that ran for 23 volumes between 1974 and 1978.

From the back cover:

WHO KNOWS WHAT EVIL LURKS IN THE HEARTS OF MEN?

Meldon Fallow, inventor, had created an extraordinary new type of engine whose secret formula would mean dreamed-of power and wealth to its possessor. But the secret was not for sale--not even for five million dollars!

Meanwhile, hard, cruel eyes were watching Fallow and his associates--the all-seeing eyes of a sinister genius who vowed that murder would achieve what money could not. And finally, death struck: grisly death, so brutal it seemed it could not have been inflicted by human hands.

Such was the work of Charg, the power-crazed master of mayhem, whom no man alive had ever seen, much less captured. Who could withstand his deadly intent! What crime-fighter was himself so cunning, so stealthy, so steeped in the ways of darkness that he could penetrate the hellish sanctum of Charg? Only one--The Shadow!

Originally published in THE SHADOW Magazine, Volume 10, Number 3, July 1, 1934.