Yes, it's a Chinese expression for prostitute, which I chose both for the beauty of the phrase and for its irony. Although a prostitute, Ah Toy cannot be described as a "daughter of joy" in any literal sense.

Ah Toy is a Chinese prostitute in the California gold rush. You're best known for writing They Saw the Elephant, a history of women in the gold rush. How does this book differ?

In the first book, I was like a mother hen herding her chicks on stage and saying, "Look! Aren't they remarkable?!" I simply collected them together and arranged their appearance. In writing a novel, the stage is empty until furnished by one's imagination. In populating the stage, however, I used several real people. Ah Toy lived. So did her enemy, Norman As-sing. Belle Cora, Simone Jules, and Irene McCready were all famous courtesans of the time. And, of course, the events are historically accurate: San Francisco's many fires, the cholera epidemic, the Vigilance Committee hangings.

With so many historical women to write about, why did you choose Ah Toy?

She fascinated me from the moment I discovered her. Her independence for that time and place, as a woman, particularly an Asian woman, was remarkable. She mastered enough English to utilize the American judicial system. She appeared in court numerous times as a plaintiff, once to sue clients who substituted brass filings for gold dust. It was from newspaper accounts of her court appearances that I learned she repeatedly said, "You know nothing!" She had a wonderfully defiant attitude-with which she successfully resisted Norman As-sing's control.

Who was Norman As-sing?

In 1849, As-sing owned a restaurant and bakery in San Francisco and was the acknowledged leader of the Chinese in California. He was as much in the news as Ah Toy. He led the Chinese in San Francisco's frequent parades, complete with silk banners and flashing-eyed dragons. He organized California's first Chinese benevolence society, the foundation for the Chinese Six Companies still intact today. I was fascinated by his ambition and his eventual embroilment in Triad activities, with Ah Toy testifying against him to secure his indictment.

The Triads in San Francisco, the so-called Chinese war at Weaverville, the discrimination in the gold fields, all that is factual?

Absolutely. California hosted a huge Chinese population as early as 1852. Threatened by the increasing numbers, some counties and mining districts prohibited them from owning mines. Discrimination against Chinese miners frequently resulted in robbery and even murder. Trinity County offered a kind of sanctuary to Chinese miners, primarily because the foreign miners' tax, levied principally against the Chinese, funded the county coffers. The Weaverville war, which occurred there in 1854, resulted from a conflict between warring Chinese factions goaded into battle by Americans who wanted to see them fight.

You're obviously intrigued by historical events. Why are you writing fiction?

History, delivered plain, rarely touches the emotions that define us, that make us interesting to one another. Newspaper accounts hint at Ah Toy's scorn and defiance, but that's only a fraction of who she was. She must have felt the whole range of human emotion: loneliness, anger, envy, love, despair. And as an immigrant she must have felt fear, amazement, isolation. Historical fiction permits us to get inside other people's lives, to imagine what it must have been like to be a Chinese woman witnessing California's gold rush. That event was a peak moment in world history, not just our own. Gold was California's siren call to the world, and the world answered with a cosmopolitan population. I wanted to capture the immigrant experience in the gold rush, particularly that of the Chinese.

Why particularly the Chinese?

Several reasons. First, my fascination with Ah Toy. Second, the Chinese culture is so different from our own. I loved researching and writing about temples and fortune tellers, customs and beliefs, a Chinese funeral, a Chinese wedding. Third, in the 1850s, long before "Pacific Rim" became a catch phrase, China was California's trading partner. Later, Chinese labor built the levee system that made agriculture what it is in California. And, of course, it was Chinese labor that built the railroad connecting California to the Union. The contributions of the Chinese have been critical to California's development. I wanted to honor that.