The novel is generally believed to be based on Aleister Crowley's own drug experiences, as suggested by his preface statement of "This is a true story. It has been rewritten only so far as was necessary to conceal personalities." Crowley's use of recreational drugs, as well as his ongoing battle with addiction, especially to heroin, is widely documented. He extensively studied the effects of drugs on both body and mind, often testing them on himself. This novel is a reflection of Crowley's philosophy and the concept of True Will that is core to Thelema.