In The Quest of the Sacred Slipper, terror comes to Britain when a self-centered archeologist unearths one of Islam's holiest relics -- the sacred slipper of the prophet Mohammed. Until it is returned to its rightful people, the implacable Hassan of Allepo vows his reign of death and destruction shall not cease. Behind these inhuman outrages is a secret group of fanatics. Not even the best men of Scotland Yard seem able to apprehend them. For, in some mystical way, this phantom band had never been seen or even heard . . .