Thriller writer Barry Eisler was in town last night with some great stories about his John Rain series.

Rain is a likable assassin. Remember, this is fiction.

Eisler was at the Once Upon a Crime book store in south Minneapolis as part of a tour for his new book, "Fault Line," which is a stand-alone thriller. (No Rain.) But Ben Treven, the hero in this book, is a pretty likable guy, too, a  special-ops agent, and Eisler said last night he's got a second Ben book in mind.

Eisler worked for the CIA for three years, and his characters are well-versed in covert operations: things Eisler learned in the Company or from friends who still work there.

Someone asked if the CIA ever objected to any of his manuscripts, or requested that he not use certain information.

No, Eisler said. Because he didn't tell them about the books, at least not at first.

"One thing the CIA taught me was that it's better to seek forgiveness than ask permission. So I feel like I was honoring my former employer," he said.

But with one of his later books, friends at the CIA invited him  to the Langley headquarters to give a lecture about the books. The appearance was mentioned in the CIA newsletter (the Company has a newsletter?) and one of the bureaucrats noticed, and sent a letter wondering why he hadn't submitted his manuscripts for vetting by the agency.

Eisler's response: When he signed the secrets act he assumed it prohibited revealing actual secrets, and his work is fiction. But he did have another manuscript in the works, and offered to send that one in for approval, with the provision that they needed to act quickly, because of the publishing deadlines.

He sent it in, and never heard a word. Ever.

Another time, his U.K. publisher decided to put the CIA seal on the cover of one of his books. Just to be safe, they sent a letter to the CIA seeking permission. When they didn't hear back, they went ahead and  printed the cover and sent the books out to bookstores in advance. That's when the CIA notice came: They would not authorize the use of the seal.

The publisher panicked and scrambled to retrieve all the books before they were put out for sale. Eisler said he tried to convince them to go ahead and use it: The CIA would never sue, and if they did, it would be terrific publicity. But the publisher caved.

Eisler's books always feature exotic locales: Bangkok, Macao, Paris, Tibet. He said he loves doing the travel research, and, even though his friends think it's a fabulous boondoggle, he said being on the ground, searching out the places his characters would stay, and eat, and kill, gives the books an essential feel of reality.

And he talks with experts about martial arts, and killing, and surveillance, to be sure he's got the details right.

In particular, he wants to accurately portray violence. Some experts, he said, "are twisted."

"I was talking with some doctors about how to kill someone and make it look like a natural death and they gave me these suggestions. Then one guy said, 'Or you could try this, or this.' But I said, 'That's enough, I get the idea.' "

Even after consulting with experts about martial-arts moves (he has a black belt in judo, but likes to include other martial arts, too) or police tactics or surveillance moves, he takes his finished passages back to these experts, for a final review.

"And almost always, they find one little item that just doesn't seem right, that needs tweaking. And after I fix it, I figure that even the experts who read the book will think I must be an expert, too."