As the story opens, Madrid is huddled on a South Downs hillside near Ditchling Beacon. He has been persuaded by his domineering and lubricious editor Bridget to spend Walpurgis Night, 30th April, camping beside a supposedly haunted prehistoric burial chamber where occultist Aleister Crowley - aka the Wickedest Man in the World, and the Great Beast - tried to raise the devil.
All Madrid manages to raise is a girly-scream when, after a bottle of beaujolais and an attack by rampant cows, he discovers a man hanged by his ankles in a nearby graveyard.
Madrid books a room in the local pub to investigate the death and the goings-on at the local mansion, Ashcombe Manor, which has been turned into a New Age conference centre full of dubious characters. Add to the mix an old friend of Madrid's who is shooting a movie about Aleister Crowley in Brighton Pavilion accompanied by various egomaniac method actors, and you have a highly-readable romp. The only thing that's serious here is the craft of the writer!