I desire to state that I, personally, have never assisted at, or participated in, any ceremony connected with Magic – Black or White.
The literature of occultism is so immense that any conscientious writer can obtain from it abundant material for the background of a romance such as this.
In the present case I have spared no pains to secure accuracy of detail from existing accounts when describing magical rites or formulas for protection against evil, and these have been verified in conversation with certain persons, sought out for that purpose, who are actual practitioners of the Art.
All the characters and the situations in this book are entirely imaginary but, in the inquiry necessary to writing of it, I found ample evidence that Black Magic is still practised in London, and other cities, at the present day.
Should any of my readers incline to a serious study of the subject, and thus come into contact with a man or a woman of Power, I feel that it is only right to urge them, most strongly, to refrain from being drawn into the practise of the Secret Art in any way. My own observations have led me to an absolute conviction that to do so would bring them into dangers of a very real and concrete nature.
Dennis Wheatley