Scott Westerfeld.
Photo: Theo Black.

Scott Westerfeld hit the bestseller lists in 2006 with his Uglies series, set in a dystopian future where 16-year-olds are forced to undergo radical cosmetic surgery to perfect their looks. How to follow that act? Go to the past, but add genetic engineering.

Leviathan will be published by Simon & Schuster in October, first in a planned four-book series (three novels and a heavily illustrated “manual of aeronautics”). It imagines a WWI fought with hybrid creatures, living products of Charles Darwin's 19th-century discoveries about DNA and bioengineering.

Because Westerfeld wanted the finished book to have the period feel of the era in which the story is set, S&S is using 70-pound paper, full-color endpapers depicting an allegorical map of Europe, and 50 interior illustrations—lavish bookmaking financed in large part by Westerfeld himself.

“It's completely nutty, but this story pushed most of my buttons—steampunk, airships, military history,” Westerfeld says. “I thought, 'What if I never have another huge series?' This was my chance to take the leverage I had earned with Uglies and do something with it.”

Westerfeld's inspiration began with A Trip to Mars, a 1906 science fiction novel by Fenton Ash that featured full-color illustrated plates but no female characters. “There was a King of Mars, and a Prince of Mars, but typical of books written in that era, no Princess of Mars,” Westerfeld says. “I wanted a story that had the same look and feel of something like Boys' Own Adventures, but would appeal to girls, too.”

Roughly following historical contours, Leviathan opens with the assassination of Archduke Franz Ferdinand and his wife, but focuses on their surviving son, Alek, who escapes death. In alternate chapters, readers get to know Deryn Sharp, a girl so intent on joining the British Air Service she's willing to disguise herself as a boy. Alek and Deryn meet, join forces, and WWI is on. In Westerfeld's re-imagining, the combatants are the Clankers, whose weaponry consists of heavily fortified machinery, and the Darwinists, whose airships are made up of bioengineered animals. The Leviathan is the most colossal of these: a giant whale kept afloat by microscopic hydrogen breathers.

Westerfeld had already written 16,000 words when, surfing for inspiration on the Web sites of artists who specialize in steampunk and Victoriana, he decided the book had to be illustrated. “Steampunk culture is crafty and very visual. People make their own clothes and toys and props, and I found the book had to reflect that,” he says.

Westerfeld hired Keith Thompson, a Canadian who does conceptual art for feature films and video games, based on his online portfolio. “It's entirely an e-mail relationship. We've never even talked on the phone,” Westerfeld says.

Thompson, who lives in Ottawa, had previously published three art instruction books, but had never collaborated on a novel. He asked Westerfeld for a month to research and spent the time in the library reading back issues of Punch magazine from 1914. “Anytime I query something—is that dress right?—10 minutes later, he sends me a photograph from the period,” Westerfeld says.

As with many writers, Westerfeld's path to writing for kids was not straight. After being laid off as a textbook editor in 1996, he wrote three SF titles for adults—Polymorph, Fine Prey and Evolution's Darling—before receiving a fateful request from a friend: did he have any ideas for a paranormal TV series? The idea Westerfeld came up with, five teenagers with special powers all born at the stroke of midnight, didn't sell, but the concept intrigued him. When he decided to convert it to a book series (called Midnighters), he realized he had switched audiences.

“Staying up till midnight when you're 25 is not that magical so it just seemed like it had to be for kids,” he says. “And then I had so much more fun writing in YA. I just like the people in it, and it's great to have all these champions among the librarians. The books last a lot longer.”

Westerfeld will tour for Leviathan in October. He is an accomplished traveler, spending half his year in the U.S. and the other half in Australia, birthplace of his wife, YA novelist Justine Larbalestier. (He says they are “bisummeral, moving between the hemispheres to avoid the deadly scourge of winter.”)

At the moment, he and Thompson are finishing Leviathan's sequel, titled Behemoth, which has a fall 2010 release. Westerfeld has found that the back-and-forth process of collaborating with an artist has invigorated his writing, allowing him to build on Thompson's equally inventive imagination. “I find I'm punctuating my chapters with things that will be more dramatic and interesting to illustrate, or I'll tell Keith, 'I want something to chase them here. You draw it, and then I'll write it in.' ”