"The Illuminatus! Trilogy" is a series of three novels written by Robert Shea and Robert Anton Wilson. Published in the 1970s, the books blend elements of science fiction, conspiracy theory, and satire. They explore themes such as the nature of reality, the influence of secret societies, and the interplay between order and chaos. The trilogy consists of "The Eye in the Pyramid," "The Golden Apple," and "Leviathan." It features a wide array of characters and plots, including references to historical events, occultism, and various philosophical ideas. The narrative style is nonlinear, often incorporating humor and absurdity to challenge conventional thinking.