The best-selling science fiction author has envisioned a postapocalyptic Oregon in his Emberverse series—complete with swords, castles, and a neofeudal empire centered on Portland. As he embarks on the eighth novel in the series, Stirling, who currently resides in New Mexico, opens up about the Rose City’s chances of survival at the end of the world.

The apocalypse is a venerable tradition in science fiction. It enables you to avoid the embarrassment of trying to write in the near future. If you write something set five years from now, you’ve got a ticking deadline, after which you’ll look completely ridiculous. Alternate histories, postapocalyptic or time-travel stories, they help you avoid that. My own conviction is that if you’re going to write in the future, you should write in the far future, when everything today is legendary.

The books start with “the Change,” which happens on March 17, 1998. There is a flash of light, a moment of intense pain, and all higher-energy technologies stop working. No electricity. No combustion engines. No explosives. Essentially, modern stuff doesn’t work.

The average city has a two-week supply of food. There’s no way to distribute it, there’s no way to communicate, no way to exchange information. You can’t even haul stuff on the roads because they’re blocked with cars that just stopped. No way to fight fires. No way to treat sewage. It’s a compendium of disasters.

Readers enjoy these stories because they like to think, “What would I do?” And in 99 percent of the cases, the answer would be: “Die.”

One of the things I like about this series is that I’ve given myself a canvas that has everything. I’ve got knights in armor, I’ve got neo-Celts, I’ve got cowboy stories, I’ve got Indians, pirates, you name it. I write for fun, and I read for fun. If it’s not fun, I’m not doing my job.

Before I started the series, I saw a long valley running north and south between mountains. For a little while I wasn’t quite sure whether it was the Willamette or the Shenandoah. Then I decided the Shenandoah was too close to the eastern megalopolis. And there were certain demographic things about the Northwest that were right for the story. Like there’s a heck of a lot of Wiccans in the Northwest, which figure prominently in the book.

The Pacific Northwest is the promised land of the bicyclist. We tend to lose sight of the fact that if you don’t have mechanical transportation, a mile is a long way. When the apocalypse hits, the bicycle becomes a serious political factor.

I needed a palace, and I wanted something fairly spectacular. I consulted my native guides, and one of them suggested the Multnomah County main library. It looked just right, both the location and the architecture. That becomes the city palace of the Lord Protector of the Portland Protective Association. The Park Blocks not far from the library become a jousting ground. And there’s a very large castle built just south of Portland.

Survivors tend to be mentally flexible. That’s why they contain a large percentage of rather eccentric types: they were mentally uncoupled from the status quo to begin with. It’s easier for them to assume that things have drastically and permanently altered. Anyone who sits waiting for the National Guard to arrive is toast. There’s a somewhat higher percentage of eccentrics in Portland. I’m afraid Seattle is completely wiped out.

Tears of the Sun will be published in September 2011.