I’ve been lucky enough to write with James Patterson for the past two and a half years. Before that I’d written eight novels, including Rogue, been published in multiple languages, sold books into movies, and been nominated for and won various awards. In short, I thought I knew what I was doing when it came to commercial fiction. Working with Patterson, however, I discovered quickly that I didn’t.

I’d always worked organically, starting a tale to see where it took me and then figuring out an outline if the story showed promise. My coauthor forced me to think logically and deeply through every scene up front, long before we even thought about writing.

During the eight weeks it took us to craft the outline of Private Berlin, for example, Patterson was constantly pushing the envelope, from the premise to the characters, from the action to the setting. In conversations that took place on a weekly basis, he bluntly criticized my initial efforts, made me want to be better, and in so doing gave me a master class in commercial fiction. What I’ve learned from the global bestselling author could fill a book, but here are some of the lessons that have changed my writing life.

We are in the business of entertainment, not edification or enlightenment,” Patterson told me very early in our working relationship. “We are interested in giving the reader an intelligent thrill ride populated by outsized people we feel for.” Characters, especially heroes and villains, were to be thought about carefully. They had to be human, above all, and then we had to subject them to terrible ordeals that took them to the brink of their capacities and beyond.

“To do that, our villains must be worthy opponents,” he lectured me repeatedly. “The reader has to believe that the bad guy is fascinating enough, clever enough, and bad enough to defeat our hero.” Research was the basis of great villains. It was also the basis of hero, plot, and believability. Patterson is extremely well read, and his statements about writing are often peppered with references to specific authors, books, or films. In one villainous discussion he urged me to read the poetry of Louise Glück to get a better feel for a lacerating voice. In another we discussed the novel Perfume.

Exposition was severely limited. The old adage—show, not tell—was critical, and the element of surprise was paramount. Each chapter in Private Berlin had to deepen a character, advance the plot, or turn the tale on its head. You began every scene with the end in mind; and the end had better blow the reader’s mind or it would be revised or tossed.

Then there was the writing itself.

“What most people who attempt commercial fiction don’t understand is that you have to write the way people talk,” Patterson told me at our first meeting. “You can’t make the prose rigid or dense and expect the normal, busy reader to turn the page, much less stick with you to the very end.” He advised me to imagine an entertaining bon vivant in a bar telling our stories in a language that would appeal to every Tom, Dick, and Mary in the place. Humor helped. So did a flare for the dramatic. So did a pared-down style. My coauthor has been criticized for the short chapters and the ultra-lean prose, but don’t think for a minute that it is without purpose beyond a quick read for a harried reader.

“Most writers will tell you five to 10 things about a character or a setting or an action,” he told me. “Fine for literature. But our approach is to pick the one or two or three that really count and discard the rest. It not only creates pace but it leaves images in the reader’s mind that are concrete and unequivocal.”

The sum of this advice was to sacrifice all for the story and the characters. Outlines were trusted navigational charts, yet we were free to sail in other directions as the novel evolved. But if you were going to change something, it had to be a terrific change. “We’re after terrific, fascinating, and smart,” Patterson said. “We’re after a story that the reader can’t put down and can’t forget when they’re done, the kind people talk about to their friends.”

Now, as I work on the sequel to Rogue, I keep hearing Patterson’s soft, gravelly voice prodding me to make every scene sharper, more human, and more terrific. I have the distinct feeling his lessons and advice will guide me every day for the rest of my career.