1879. After three surviving members of an expedition to the Sahara are killed, the last, Lord Wellington, agrees to speak with Sir Edward Grey. He tells of strange bones discovered by the group amidst a subterranean civilization, but no sooner has Wellington begun to name the man who took custody of the seemingly cursed bones than he is struck dead, a creature appearing above him and attacking Grey. Following a rooftop chase, Grey -- the man whom whispers call Witchfinder -- is handed a mysterious note at Wellington's autopsy.