08/16/2013 02:07 pm ET Updated Oct 16, 2013

Switching From Nonfiction To Fiction

I made the whole thing up. In my most recent book, I described a medical condition afflicting certain surgery patients, patients referred to (after a German research paper that I also just made up) as die Wiedergänger: returners who never fully surface from anesthesia. Seemingly functional after their operations, they remain in a semi-stupor, unable to forget their journey to oblivion, how "in the course of outrunning pain, they'd traveled to the border of mortality."

Never mind that this condition was a thorough fabrication. Citing counterfeit documentation, I described its symptoms in scientific detail.

I'm not usually given to lying. I've spent a journalism career training myself to never state anything inaccurately. The greatest professional shame I could imagine was the misstated fact. The possibility that I might allow into print something I'd only imagined terrified me.

So it was no small departure, with this latest book, my third, to desert nonfiction. Paris Twilight is a novel. When I began work on it, I felt a subversive thrill--you mean, I can say whatever I want? I also felt the constraint of old training, a fear of straying wherever my imagination led. It was hard letting go of the security of facts--what would be left to guide me?

I needn't have worried. I soon learned that I wasn't free at all, that writing Paris Twilight was just as meticulous a search for accuracy as anything I'd done. Sure, I could make up my characters, but once summoned, they arrived on the page with intact identities I couldn't violate--with histories and personalities I knew nothing about, and had to discover. My writing every day felt like the interview stage of reporting a factual story. I'd listen carefully to what the characters told me, and try to get it down as faithfully as I could. If I strayed from the truth, the narrative ground to a halt. And then I'd have to do what I always do: consult my sources, listen to them carefully, and get their stories straight.

I've never had such willful sources. I might think someone (in this case, a shadowy diplomat) was gone for good when he exited the room on page seven, but here he was back again, fifty pages later, to seize a major role in the plot. My heroine, Matilde Anselm, who narrates Paris Twilight in the first person, says things I could never have known. Including medical things. Matilde is a cardiothoracic anesthesiologist, at age fifty eminent in her field, who is called to Paris from New York to participate in a heart transplant. She dictated reams of medical lore to me, how anesthesiologists and surgeons live by opposing creeds, what it's like sending people into temporary comas. It was Matilde who informed me about the twilight delirium afflicting die Wiedergänger revenants, a condition descriptive of her own long-slumbering, soon to be awakened, emotions.

Oh, I admit to doing some independent research, consulting existing texts and living experts on such topics as Spanish Civil War history and the traditions of Islam, two elements that drive the plot. When Matilde pushed deeper into the technicalities of surgery--I follow her step by step through one harrowing transplant--I reverted to my reporter self and scrubbed in with a surgical team at Massachusetts General Hospital, and observed some open heart surgeries. Such surgeries had nauseated me when I watched videos of them on YouTube; in person they were so fascinating I forgot my squeamishness altogether.

I learned, to my astonishment, that the testimony of my imaginary characters could be spookily accurate. A (made-up) Parisian attorney described to me a species of wildflower that grows in the Pyrenees. I later went to Wikipedia to find the name, oreja de oso, but I didn't have to correct his taxonomy at all. I'd expected my writing to conspire with my own hidden psychology. I'm still flummoxed by the ways, in instance after instance, my characters conspired with the outside world to present a factual landscape: characters proposing, and the world corroborating. Was the palatial secret Paris apartment Matilde breaks into, embalmed untouched since World War II, really plausible? I wondered. Then a news story hit the French press of exactly such a specimen (though the real apartment had million-dollar paintings on its walls). The Sunday after two of my characters endured a wrenching romantic encounter late on a snowy night beneath the branches of a giant English elm in Washington Square, the New York Times Magazine ran a full-page photograph of that self-same tree (in a profile of a tree photographer), as bare-limbed as I'd conjured it.

What's an old-school disciple of fact supposed to do with this strange new avenue of knowledge? At a brunch near Harvard Square, some months after I'd sent in my final manuscript, I introduced myself to the stranger sitting across the table, a doctor, it turns out, in from Germany to conduct research on a newly recognized syndrome in surgery: it seems that many patients don't surface fully from anesthesia after an operation, she said, but exist perpetually in a sort of partial dream state, or stupor.

"It's . . . after any sort of surgery?" I stumbled. She nodded.

"Especially heart operations, for some reason," she said, and said the phenomenon was so unstudied they were struggling to gather accounts by its sufferers, these . . . these . . ."

"Die Wiedergänger?" I suggested.

"A perfect description!" she declared, and I let the matter lie. I didn't offer her Dr. Matilde Anselm's resume. I wasn't sure I knew how to explain to her where I'd got my facts.