Canongate is a 40-year-old independent U.K. publisher with offices in a 16th-century building in the Old Town section of Edinburgh. Francis Bickmore, the publishing director of Canongate, shares an architectural detail: “The Fear of the Lord Preserveth the Lyf” is carved into the interior stone wall. Fitting, since Canongate’s “super lead title,” The Way of All Flesh by Ambrose Parry, which Bickmore edited, is an historical novel set in 1847 Edinburgh.

“I love that the atmosphere of Edinburgh is captured on the page,” Bickmore says. And it certainly is: “The smells of ordure were inescapable around here, so many lives piled one upon the other in the foetid labyrinth that was Old Town.”

The book opens with a promise of intrigue: “No decent story ought to begin with a dead prostitute.”

Bickmore calls the novel a celebration of Edinburgh in the 1840s, a time when the city was at the forefront of medical discoveries. James Simpson, a Scottish obstetrician, was pioneering the use of liquid chloroform and revolutionizing surgery. Before chloroform came along, Bickmore tells me, patients were restrained and made to “bite down on wooden sticks.”

Ambrose Parry is a pseudonym of Chris Brookmyre and Marisa Haetzman, a husband-and-wife team with an interesting mix of skills. Brookmyre is a bestselling crime writer whose 21 books are all contemporary or set in the future; Haetzman has been an anesthesiologist for 20 years, and Bickmore notes, is “probably the only person I’ve ever worked with who could save my life.”

Haetzman stopped practicing to get a master’s degree in the history of medicine at the University of Edinburgh, and while researching Simpson, uncovered fascinating stories. Combined with the goings on in 1840s Edinburgh, the extremes of high brow and low, and, as the couple has said, “the colorful nature of Simpson’s domestic arrangements,” Haetzman thought there were the perfect elements for a historical mystery.

With his openness, which defied the stuffiness of the Victorian era, Simpson became a central character. “The Way of All Flesh is the first in a series that Chris and Marisa want to create around Simpson and his house,” Bickmore says, “which was a revolving door for all sorts, from the aristocracy to the poorest of the poor.”

In the novel, young women are being gruesomely killed across Old Town, and Simpson’s housemaid, Sarah, an intelligent young woman with ambitions, and his apprentice doctor, Will Raven, an unreliable rogue, team up to solve the murders. Sarah takes an instant dislike to Raven (he has the privileges that she’s denied; an underlying theme of the book is how women were restricted by this society), but there’s chemistry, of course, and I’m not giving anything else away.

Bickmore remembers first hearing about the book outside the Spiegeltent at the Edinburgh International Book Festival while having drinks and talking to Brookmyre. “We hadn’t worked together at this point,” Bickmore says. “He started telling me about a secret project he was working on with his wife, and from what I was hearing, I said I couldn’t think of a piece I’d be more excited to see.”

When the manuscript arrived at Canongate, from Sophie Scard at United Agents in London, in late 2017, Bickmore was enthralled and says everyone else felt the same way. “A consensus is not at all common in publishing, it’s actually rare, and I swiftly preempted it,” he says. He bought world rights for a “substantial sum” and SunnyMarch quickly preempted TV rights, with plans to adapt the novel into a drama series.

With historical fiction, Bickmore tells me, “there’s the danger that it’s repeating a formula, but The Way of All Flesh is genre breaking; it bends the rules.” He adds, “It has the pacing of crime fiction but in an historical setting. We wanted a book that would keep you up all night reading. Chris is a master at plotting, suspense and pacing; Marisa brings three years of research and the historian’s eye for detail.”

Brookmyre is a longtime client of Caroline Dawnay at United Agents; Scard began jointly representing him with Dawnay about five years ago. “But with Ambrose Parry,” Scard says,“I became the sole agent in order to make the distinction.”

Scard tells me that she and Dawnay knew Brookmyre was working on something but saw nothing until the couple sent in a few early chapters in February 2017. “We gave a few suggestions and in early October the manuscript for The Way of All Flesh appeared. We were all very excited. I tweaked it a bit and sent it out at the end of November 2017 to about a dozen publishers. Three days later, Francis [Bickmore] called and made an offer.”

Scard says she called Brookmyre and they talked back and forth. Forty minutes later, they had a deal. Scard thought the book was “brilliantly executed” and the characters so relatable “even though they are from another era.” She also thought that Brookmyre and Haetzman were “very brave” to write a book together. (Scard and I agree that writing a book with a spouse is not something either of us would ever think of doing.)

Like Bickmore, Scard emphasizes that this book is a wild departure for Brookmyre. “You wouldn’t know Chris had anything to do with it,” she says. “It’s a different voice, a different style—such attention to aesthetics, details, interiors.”

When I speak with Brookmyre and Haetzman, I understand how they wrote a book together. Maybe it was the lilting Scottish brogue, but they came across as paragons of calm.

“Every night Marisa had another story about Simpson and the transformations that were taking place in Edinburgh [in the 1840s],” Brookmyre says. Haetzman completed her master’s degree in 2014 and they talked about a story for a couple of years. In January 2017, they began in earnest.

“We weren’t reluctant to collaborate, but didn’t quite know how it would work out,” Brookmyre says. They imagined at first that Haetzman would do the research and Brookmyre would shape the story, but Haetzman developed ideas and characters, Sarah in particular, because, Haetzman says, “I had time while Chris was working and I was waiting for him to be available.”

For the character of Raven, the apprentice doctor, Haetzman was invaluable because she had all the medical details. And when she was researching Simpson, she was able to see his original case notes, in his own handwriting, at the Lothian Health Services Archives at the University of Edinburgh.

Brookmyre says that he had always wanted to write a historical novel, but under his own name he produces a book per year (he’s working on one right now) and couldn’t imagine finding the time. “But with Marisa, I had the perfect partner,” he says. “It’s great having a collaborator. My contribution was making it all darker, and far more complicated.”

Canongate is publishing The Way of All Flesh in the U.K. in August and in the U.S. in October. It will be distributed in the States through PGW. Bickmore says there was a temptation to license it to one of the American houses, but after exploring options, Canongate decided to go through PGW. Foreign rights have been sold to Canada (HarperCollins), Denmark (Modtryk), Germany (Piper), Italy (Rizzoli), Poland (Zysk), Russia (Eksmo), and Spain (Salamandra). Bickmore expects more deals to come at the London Book Fair this week. Plans are still underway for the U.S. launch; 2,500 ARCs will be available at BookExpo.

I still can’t quite let go of the idea of a husband and wife from such wildly different professional backgrounds writing such a thrilling and seamless book. How did they do it without killing each other? Both told me that it was “mostly harmonious,” but after I keep prodding, Haetzman finally breaks down.

“Well, I’m the historian and all about the facts,” she says. “I’d question something and Chris would say, ‘Oh that’s fine, we can just make it up—it’s a novel!’ But I wanted everything accurate, and was very, very fussy about everything being true.”