The book starts off a bit preachy, repeatedly explaining that if you don't do what Brooks recommends, your chances of being published (or just writing a good novel) will be greatly reduced. This point is made repeatedly throughout the book. That could be off-putting for some readers, but I recommend skimming those parts when you encounter them. The rest of the material you find in the book will more than balance things out.
At a very high level, Brooks recommends a four-part story format. While this sounds dangerously like a formula, it's really not. It's just a basic structure to help you organize the story you're trying to tell. In order to fit this into a blog post, I'm intentionally over-simplifying the structure, and describing it as a standard "hero/villain" story where two people are in conflict over something. Just be aware that this is explained far better, and in far more detail, in the book.
- The Setup – Introduces the hero and shows us what his life is like before the villain enters the picture. We learn what the hero has at stake, what his inner demons are, and his point of view. It ends with the hero becoming aware of the opposition and realizing that action should be taken.
- The Response – The hero now has a purpose or a "quest" to undertake. He responds to this, perhaps by making a decision (or wrestling with indecision). He's hiding, strategizing, planning, observing, recruiting help, and getting ready to take action. It ends with the hero ready to take action, and go on the offensive.
- The Attack – The hero starts trying to set things right. But things aren't static on the villain's side. The hero learns that the opposition is stronger than he thought. He suffers a defeat or two. It ends with a revelation or a proverbial new door opening, empowering the hero with the weapon or knowledge needed to finally win.
- The Resolution – The hero summons the strength and resources to finally reach his goal. The villain is vanquished, and all the loose ends are tied up.
Earlier, I posted an article on creating three-dimensional characters. It was derived from what I learned in Story Engineering.
The bottom line? I learned more from this book about story planning, story structure, characterization, and foreshadowing than I have from any other writing book I've read. It's helped me to re-evaluate the three novels I've written to date, and understand why I was so disappointed with each of them. I even have ideas for making them (and novel #4) better. I definitely recommend this book.