During the 1970s and early '80s, dozens - perhaps hundreds - of Japanese civilians were kidnapped by North Korean commandos and forced to live in 'Invitation Only Zones', high-security detention centres masked as exclusive areas on the outskirts of Pyongyang.

The objective? To brainwash the abductees with the regime's ideology and train them to spy on the state's behalf. But the project faltered; when indoctrination failed, the captives were forced to teach North Korean operatives how to pass as Japanese, to help them infiltrate hostile neighbouring nations.

For years the Japanese and North Korean authorities brushed off these disappearances, but in 2002 Kim Jong Il admitted to kidnapping 13 citizens, returning five of them - the remaining eight were declared dead.

In The Invitation Only Zone, Boynton, an investigative journalist, speaks with the abductees, nationalists and diplomats, and crab fishermen to try to untangle both the kidnappings and the intensely complicated relations between North Korea and Japan. The result is a fierce and fascinating exploration of North Korea's mysterious machinations and the vexed politics of Northeast Asia.

Robert S. Boynton is the director of NYU's magazine journalism program and is the editor of The New New Journalism. His journalism has appeared in The New Yorker, Harper's, The Atlantic Monthly, The New York Times Magazine, The New York Times Book Review, and many others.