With the theft of the sacred slipper, rumored to have been worn by the great Prophet himself, came a wave of outrageous horror. Weird, supernatural feats accompanied its movement from the Near East to a London museum. Mutilation, even murder, threatened all who came near it. It was as if a horde of phantoms had descended upon London, whose guardians were soon plunged into fear and dread. And then the truth emerged. Behind these inhuman outrages was a secret group of fanatics--Assassins--trained from childhood to wreak havoc on all who dared disturb their sacred relics. Not even the best men of Scotland Yard seemed able to apprehend them. For, in some mystical way, this phantom band had never been seen or even heard...