March 12 (Bloomberg) -- Barry Eisler’s path from CIA operative to best-selling novelist is strewn with a decade of judo mats, jazz bars, legal opinions and 50 rejection letters.

His debut, “Rain Fall,” introduced John Rain, a half- Japanese, half-American killer who specialized in “death by natural causes.” Rain used tactics derived from the author’s own three years in the Central Intelligence Agency, black belt in judo and interest in what he calls “forbidden knowledge, stuff governments want only a select few to know.”

Now, after six thrillers featuring his beloved assassin, Eisler presents a new cast in his latest book, “Fault Line.”

Brothers Ben and Alex Treven, estranged and embittered by a family tragedy, find themselves forced to rely on each other, and their very different talents, to escape a deadly conspiracy. The book melds Eisler’s CIA background with his experience as a technology lawyer and Silicon Valley start-up executive to make the Treven brothers as credible as Rain.

“It has a lot of the same elements people like so much about the Rain books,” Eisler, 45, said during an interview in Bloomberg’s Tokyo bureau.

“There are exotic locales, in this case Istanbul. I try to keep the tactics and scenarios as realistic as I can, drawing on everything I learned in the CIA so people are behaving and thinking the way they really do in these situations.”

Cryptography Deal

As the book opens, Alex Treven is minutes away from the deal of a lifetime on a cryptography breakthrough that promises to make him both rich and a legend in Silicon Valley. Then it all goes horribly wrong in ways he’s unequipped to handle. Big brother Ben, a covert agent in the War on Terror, is the last person Alex wants to beg for help but the only resort he has.

Eisler throws in a stunning Iranian-American love interest, who brings along her own issues and talents as the three uncover the truth, find out who can and can’t be trusted, and try to survive.

A self-described “news junkie,” Eisler builds his plots against the background of current geopolitics and world events. “Fault Line” incorporates terrorism, Iran’s nuclear ambitions, Russian mafia hoods and the potential that high-level data encryption offers for disrupting global networks.

“When I was about 20, I got really interested in the world, in what’s going on out there,” says Eisler, who arrived for our talk in a dark blue shirt and brown sports jacket. “So I began reading all kinds of magazines, books, newspapers, and it became an enduring hobby, or fascination of mine which continues to this day.”

Writing and Rewriting

Eisler, who now writes full time in the San Francisco Bay area, draws inspiration from his past as a technology lawyer in Japan. His genesis as a novelist came one day in a Tokyo subway station when the image popped into his head of two men following someone down a street.

“Who are they? Why are they following him? OK, they’re planning to kill him! But how? Why?” Those questions led to eight years of writing, rejections, rewriting, more rejections and polishing before “Rain Fall” was finally published in 2002.

In five subsequent books, the hit man’s protective shell of amoral cynicism develops fault lines of its own, as an aging mentor, two love interests and a sniper with a heart of gold infect his world with the humanism he long rejected as weakness. Books in the series have won the Barry and Gumshoe literary awards and sold some 1 million copies in almost 20 languages.

Correcting Mistakes

Eisler carries on a continuing conversation with readers on his official Web site, where he offers advice to would-be writers and joins discussions about character, motivation and plot. One engaging page on the site offers his Top 10 list of Tokyo bars, coffee shops, restaurants and jazz haunts. The site also contains a section called Mistakes, where Eisler invites readers to tell him when he drops the ball.

“I do a ton of research. Every place I write about, I’ve been there. I walk in the footsteps. If I’m writing about firearms or surveillance technology, I’ll always talk to an expert and have him read the scene,” he says. “But occasionally something slips through, and when that happens I want my readers to know they can count on me to try to correct it in a subsequent edition.”

Rain fans needn’t worry that their hero’s journey is done. Eisler says on his Web site that he might return to the series, perhaps with a closer look at how the assassin got started. A follow-up book on some of the protagonists in “Fault Line” is another possibility, he says.

Meanwhile, Eisler is getting ready to enjoy the April premiere of a Sony Pictures film based on “Rain Fall” and starring Japanese actor Kippei Shiina as John Rain and Gary Oldman.

“Fault Line” is published by Ballantine in the U.S. (320 pages, $25).

(Jim McDonald writes for Bloomberg News. The opinions expressed are his own.)

To contact the writer of this column: Jim McDonald in Tokyo at jmcdonald8@bloomberg.net

Last Updated: March 11, 2009 20:00 EDT