They have been dubbed "bonnet-rippers" and the sex is generally left to the reader's imagination. But the subtle pleasures of a new brand of romantic fiction set in America's Amish communities is proving one of the most surprising success stories in publishing.
At a time when most bestsellers seem to involve angst-ridden teen vampires or thrillers based on murderous global conspiracy theories, authors have been quietly racking up hundreds of thousands of sales by exploring the romantic entanglements of the Amish.
At first, the Amish seem an unlikely inspiration for novels of lust and forbidden love. Scattered across the United States but most famously concentrated in Pennsylvania, the Amish, and similar sects like the Mennonites, live quiet lives in small farming communities. They eschew modern technology, often speak an old-fashioned form of German, have strong religious faith, wear 19th-century-looking clothing and bonnets and usually drive horse-drawn buggies.
Such a lifestyle has not stopped the "bonnet-ripper" phenomenon from taking off or spreading into other genres, such as Amish thrillers and mysteries. Bookseller Barnes and Noble recently reported that 15 of its top 100 religious fiction titles were Amish novels.
The numbers involved are enough to whet the appetite of a struggling publishing industry.
Author Beverly Lewis has sold 13.5 million copies of her books set among the Pennsylvania Amish; Wanda Brunstetter's novels have moved four million copies. One publisher, Thomas Nelson, is releasing five Amish novels this year and has plans for six more next year. The phenomenon has gained mainstream media attention from the Wall Street Journal and Time magazine.
"People like them for a lot of reasons. That is why they are such hot sellers," said Cindy Woodsmall, whose fifth Amish romance - The Sound of Sleigh Bells - is out next month. "The Amish are holding on to a way of life that other Americans have let go of, and I think we all want to know the story behind that," she added.
Woodsmall's sales have reached 134,000 copies and show no sign of letting up. She puts that down to the rich storytelling tradition among her Amish friends. With no televisions or computers, most Amish families have always kept alive a tradition of oral storytelling. "It is rich, rich soil for an author to work with," Woodsmall said.
Drama tends to revolve around the comings and goings at church dances, teenagers testing the limits of Amish dress codes and behaviour, or flirting with outsiders. Kisses are not common on the printed page. Sex is virtually unknown.
While contemporary issues do intrude - one novel revolved around an Amish woman trying Prozac to cure her depression rather than the power of prayer and family - most plots are set against the gentle rhythms of farming life, family and devout belief in God.
Experts say this taps into mass appeal with many Americans, who see the Amish as some sort of idealised group, living a life free from the stresses of the modern world.
Amish books are especially popular among evangelical Christians. The mild portrayals of sex and violence and the emphasis on faith and traditional family values are all strong selling points for many religious Americans.