After discovering that 1950s TV hero Rin Tin Tin was a real dog, The Orchid Thief author, Susan Orlean, embarked on what turned into a seven-year project, Rin Tin Tin: The Life and the Legend (Simon & Schuster). "It was sort of irresistible. It's partly a curiosity about why does something get remembered," says Orlean. "I feel I have always known of Rin Tin Tin," she writes in the opening of the book, "as if it was introduced to me by osmosis. It became part of my consciousness, like a nursery lullaby you can sing without knowing why."

Orlean credits her Welsh springer spaniel with inspiring her to write more animal stories—and add more animals to her home. She now has cats, chickens, ducks, turkeys, and 12 Black Angus cattle. "I think the idea of writing about animals has always appealed to me," says Orlean, "because I love animals and they're a wonderful foil for writing about people. I've written about people and plants, which to me is a fascinating relationship. This is one step further; it's really rich."

One reason the book took so long to complete was the amount of history Orlean had to tackle to tell the story of Rin Tin Tin, a German shepherd puppy found in France during World War I by Cpl. Lee Duncan. After the war, he brought him back to the U.S., where he continued to be a star. "It was a real education for me," says Orlean. "I had never thought about WWI that much, but my favorite books of the last decade were the Pat Barker [Regeneration] trilogy." In researching German shepherds, Orlean learned that they're a relatively recent breed, dating from the late 1800s. "I was flabbergasted that you can trace them back to one dog," she says. "The German shepherd would have to stand as one of the all-time engineering feats in the animal world. Once they were developed, they were popular all over the world."

Another strand of the story is orphans. In addition to Duncan, others connected with the story of the famous German shepherd, like Bert Leonard, the production manager who worked on the TV series, and Daphne Hereford, who founded the first Rin Tin Tin museum, seemed to have a hole in their families that the dog filled. "It's such a story of orphans," says Orlean, adding that being an orphan was a recurring theme in television.

Orlean also found that Rin Tin Tin functions as a Zelig figure or Forrest Gump. "Every time you turn around, he's there. That's what made it so interesting," she says. "It's almost a bellwether, seeing how we relate to our home, our space, our neighbors."

Orlean will be signing ARCs of Rin Tin Tin at the Simon & Schuster booth (3653) today, 2–3 p.m. The book will launch in October with a two-night event at the New York Film Festival.