Soon Katherine Marsh will have more to celebrate than her debut novel, The Night Tourist (Hyperion), with her first child due February 1. “It's exciting because this is who I'm writing for,” she says. “I'm creating my audience.”

Born in Kingston, N.Y., Marsh moved with her family to Westchester County outside New York City when she was five, and has ever since felt the pull of the Big Apple. “It was always a sort of a destination for us,” she recalls. “My grandparents had a bar that's now called the Life Café, but was a Russian/Ukrainian bar just after the war years. My parents met [in New York], my father went to Cooper Union. I had a lot of connections to the city.”

Marsh describes her book, a reinterpretation of the Orpheus myth about a teenager named Jack Perdu who explores the New York City underworld, as nothing less than a “love song to New York.” She wrote the book partly because she was homesick after moving to Washington, D.C. with her now-husband after September 11.

After graduating Yale, where she studied English literature, Marsh taught high school for a year, and then moved to New York in 1998. “It was this booming time,” she says. “The city was doing really well, everyone had Internet stocks, and it was an exciting time in magazine journalism, which I was working in. And that sort of ended with 9/11.”

Marsh feels that New York has itself gone through a “sort of seismic shift” since September 11. “I wanted to memorialize the city that was in my head,” she says.

Currently on maternity leave from her job as managing editor at the New Republic, Marsh wrote The Night Tourist over the course of four years, squeezing in writing time whenever possible, which generally meant an hour or two maximum each day. She notes that her editorial work and her writing “appeal to different sides of the brain,” but she has found areas of overlap as well. “I've always been interested in narrative journalism,” she says. “In the stories I edit, I'm always looking for how to make them more dramatic. So in that way the two things play off each other.”

The year she spent teaching helped her decide to write a book with a 14-year-old hero. “I really like that age, because it seemed it was this sort of cusp,” she says. “You're sort of an early teen, and there's a lot of emotional awareness. But you still have this accessibility to this world of wonder and magic, and there's a lot of drama.”

And although she jokingly describes awaiting her baby's due date as “domestic imprisonment,” she has kept busy editing the manuscript for the sequel to The Night Tourist, due next September, which will reinterpret another myth. (Universal Pictures optioned rights to The Night Tourist this past fall, so fans may see Marsh's ghostly vision of NYC on the big screen one day.) But Marsh has no plans to stop there. “I definitely would like to continue with Jack's story,” she says. “I don't think it's over yet.”