The Doctor Satan MEGAPACK®, by Paul Ernst (epub/Kindle/pdf)$0.99
Originally published in WEIRD TALES magazine in the 1930s, here is the complete Doctor Satan series -- fascinating tales about that weird genius of crime who calls himself Doctor Satan. He is no madman, but is as sane as you or I. An immensely rich man, he has turned to crime for the thrill of it, and strikes down those in his path ruthlessly, heartlessly, and thoroughly. He is master of amazing powers that make him the world's weirdest criminal. If you have not yet made the acquaintance of this fearsome master of crime, meet him today in THE DOCTOR SATAN MEGAPACK!