When a marine salvage crew discover a wreck off the South American coast, it leads to the unearthing of a sinister find - a dark and unholy cup, an equal and opposite twin of the Holy Grail. When the cup is stolen by an occult fanatic multi-millionaire, people begin to die to sate the cup's thirst for human blood. Each time the cup is fed, it becomes stronger, its goal to eradicate humanity. Detective inspector Paul Reed is thrown into a world of terrifying and bizarre events, as the seemingly mundane task of tracing the cup's whereabouts swiftly becomes a struggle just to survive. Not only has the cup been stolen, but stolen by a man who now commands the cup's protector. Once one of Hell's greatest generals, the Guardian, a demon who exists in both realms and manifests himself as a mental projection of immense power that cannot be stopped. The only hope is a half breed Sioux Indian, tasked by his ancient grandfather to journey to England and destroy the beast. Here he meets a struggling band of isolated people who find themselves the only small human bastion standing against the total genocide of the human race.