When I first met Scott Payne, with whom I co-wrote Code Name: Pale Horse—How I Went Undercover to Expose America’s Nazis, he was wearing what I would come to learn was his usual uniform, no matter the season. Backwards baseball cap, sleeveless T-shirt to reveal the bulging tattoo-sleeved arms, jeans, and cowboy boots. Looking at this man, who was my opposite in so many ways, I wondered what the hell I’d gotten myself into.

A longtime newspaper foreign correspondent and documentary filmmaker, I had also written nonfiction books before. But I had never been a co-writer. Co-writing, as I would learn, is essentially ghostwriting, but with your name also on the book. So not only would I be writing with Scott, also known as F.B.I. Special Agent Scott Payne, I’d be writing as him. I’d read J. R. Moehringer’s highly entertaining New Yorker piece, “Notes from Prince Harry’s Ghostwriter,” and most of it sounded terrifying.

Scott had first come on my radar in 2021, as I worked on a podcast series about a neo-Nazi group trying to spark a race war in the U.S. I didn’t know who he was—just that an F.B.I. undercover agent had infiltrated a Rome, Georgia, group known as “The Base,” and gathered evidence so ironclad that his targets all pleaded guilty, and the group was largely disbanded.

A few months after the series ran, I spotted a Rolling Stone profile on a retired undercover F.B.I. agent who, among other cases over his two-decade-long career, had infiltrated the Base—and I knew I had found him. What started as a conversation about a bonus episode for the podcast turned into this book.

“Why,” I recall asking Scott, after he chose me among a handful of contenders to be his co-author, “when you thought, ‘Who could embody me, a six-foot, four-inch, southern American, Christ-following, Harley Davidson–riding, bourbon-drinking, Republican undercover agent?,’ did you pick the leftie, feminist, agnostic, Canadian journalist to write your memoir?”

Scott laughed and exclaimed in his low Southern drawl, which I have now spent more than two years trying to mimic, “I thought it would be fun!”

“Fun” is an odd descriptor given the material his memoir covers. Scott had a remarkable 28-year undercover career, rivaled only by Joe Pistone, also known as Donnie Brasco, an F.B.I. agent who infiltrated the Bonanno crime family in the 1970s (the story that inspired the 1997 blockbuster Hollywood film starring Johnny Depp and Al Pacino) and who also happened to be a mentor of Scott’s.

Scott infiltrated the Outlaws Motorcycle Club, the notoriously violent arch-rivals of the Hells Angels, for 24 months, and almost lost his life, his marriage, and his mind. He experienced the depths of the opioid crisis in the mountains of Tennessee while peddling illegal cigarettes under the nickname “Mr. Marlboro” in an operation to expose dirty, drug-dealing cops. He posed as a contract killer for some sadistic, darkly comic Americans straight out of a Quentin Tarantino film.

For all our differences, we do share the love of the absurd—though his stories were so fantastical at times, I found them hard to believe. But then I found the court documents or recordings to back them up.

But it was the Base case, which took place just before his retirement, in 2021, that bookends the memoir because of its present-day significance: detailing the rise of neo-Nazi accelerationist groups in America today, whose well-armed members hope to sow chaos and start a race war.

“I’ve been doing undercover work since 1996,” Scott likes to say in summing up the year-long investigation. “And I have never had to burn Bibles. I’ve never had to burn an American flag. And I damn sure was never with a group of people that stole a goat, sacrificed [it] to their pagan ritual, and drank its blood. And I did all that in about three days with these guys.”

Moehringer writes in his piece that he’s often asked to offer advice to other writers but that there really is no universal advice, as the alchemy of each ghost-author pairing is unique.

There’s no doubt our partnership is unique—and that’s what makes it special.

In an increasingly divided world where no one talks (they just shout), in a post-truth era when “facts” pass as what the most powerful people want the reality to be, Scott and I stepped out of our comfort zones and echo chambers to listen to each other with the shared goal of exposing some ugly truths.

And Scott was right. We had “fun” doing it.

Michelle Shephard is a Canadian investigative reporter, author, and filmmaker