Thae Yong-ho was a leading North Korean diplomat to the United Kingdom and Northern Europe—until his dramatic defection to South Korea in 2016. In this gripping tell-all, he reveals the inner workings of the North Korean regime and shares the story of his decision to leave.

Thae spent nearly three decades working under three generations of the ruling Kim dynasty after entering the foreign service as an idealistic twenty-seven-year-old “red warrior” eager to strive for the “socialist motherland.” During this time, he witnessed the arbitrary and tyrannical rule of the Kim family and the enigmatic “Third Floor,” a powerful group of high-ranking officials. Thae provides up-close portraits of the excesses of the North Korean elite and the depths of the cult of personality around the Kims, describing experiences such as concocting reports of Europeans celebrating the birthdays of Kim Il-sung or Kim Jong-il and escorting Kim Jong-un’s older brother to Eric Clapton concerts in London. He also details the economic and political consequences of North Korea’s pursuit of the bomb and the immiseration of the vast majority of the population.

Today a politician in South Korea who advocates unification, Thae offers a powerful plea for the families torn apart by the conflict—including his own, as his brother and sister likely now languish in prison camps. A best-seller in South Korea, Passcode to the Third Floor is an unparalleled look at North Korean politics and diplomacy, giving readers intimate access to the regime’s innermost secrets.