Whereas Shakespeare's literary genius is universally recognized, there is also a hidden, secretive side to his work that is little known. Indeed, he used a mysterious code that figures widely in the esoteric literature of the Elizabethan and Jacobean periods. The Bard of Avon was a master of such encoding, and those who had known him continued his methods, in the Folio of 1623, as well as in his various memorials. However, Shakespeare did not invent that code. Among the many arcane authors who made use of it before him was Michel Nostradamus, the famous French prophet and savant.

As David Ovason reveals, many leading esoteric writers--alchemists, occultists, and Rosicrucians--contributed to this "Secret Booke." Among the more outstanding English literary figures who used the code were John Dee, the mysterious adviser to Elizabeth I, Ben Jonson, the turbulent author of The Alchemist, and the more classically minded Edmund Spenser, whose poem "The Faerie Queene" is the most famous esoteric work of the period. Shakespeare's "Secret Booke" reveals many other literary figures who together form a remarkable underground literary movement, including Jakob Böhme, the most influential esotericist of the period, and alchemists such as the English polymath Robert Fludd. Another was Shakespeare's contemporary, the youthful Johann Valentin Andreae, credited as author of The Chymical Wedding, a Rosicrucian work replete with sophisticated examples of encoding.

The fact that all these writers used the same or similar encoding suggests a secret teaching designed to be recognized by initiates. Ovason explores and, for the first time, reveals what Shakespeare alluded to as a "Secret Booke."