Nancy Horan Live at the Mercantile Library

For author Nancy Horan, the facts are merely an entry point. In her first book, the best-selling Loving Frank, she delved into the scandalous extramarital affair between architect Frank Lloyd Wright and Mamah Borthwick Cheney.

In her latest historical novel, Under a Wide and Starry Sky, Horan focuses on another couple whose romance pushed the boundaries of social acceptance: American art student Fanny Van de Grift Osbourne and Scottish writer Robert Louis Stevenson. The two met in France at an artists’ colony in 1876, the plucky Osbourne with 10 years on the sensitive Stevenson and a philandering husband back home.

As a writer, Horan relishes drilling narrow and deep into these real-life qualities, letting the facts guide her narrative. “By studying Stevenson’s life, I was exposed to London’s literary scene in the 1880s,” says Horan. “I loved rolling around in that history and soaking it in.” But it’s the nature of Horan’s imaginative storytelling—if an unexpected theme crops up, she’s not afraid to run with it—that makes her an appealing host for the Mercantile Library’s Modern Novel Lecture on September 29.

“Sometimes your unconscious tells you to follow a thread,” says Horan. “You only understand later why you did it.”