The Illuminati take a major role in its plot; its main protagonists are Josie Welch and Dr. Roger Prong.

Trilogy based on its publication date, it remains unclear if the actual contents of The Sex Magicians were written before or during the writing process of The Illuminatus!

Given the significant amount of time it took to find a publisher for Illuminatus, it is possible that its content was actually reused in The Sex Magicians, rather than the other way around.

However, the author also developed the logics of sex magic underlying the seemingly gruesome sexual scenes.

[1] The Sex Magicians at Hilaritas Press This article about a 1970s fantasy novel is a stub.