This book was first published in 1972, Early in Dean Koontz's career. The book reviews the basic ingredients and elements of the following genres:
Science fictio and fantasy
Suspense
Mysteries
Gothic-romance
Westerns
Erotica

It's a practical book giving insights and advice.

Really now, how many writers, early in their careers, wrote a book on how to write and then proved they could become massively successful? This is a pricey book you'll need to find used. Look for a reading copy that is not collectible because it has been well worn or discharged from a library. I don't understand why Writer's Digest hasn't re-issued this.

I wish I could get Koontz to attend the StoryCon meeting on the Art, science and Application of story, which I organize.