It is a depressing truth of some books that the stories they tell, like Tolstoy's happy families, resemble each other enough to constitute a genre. To make that observation of the genre to which The Aquariums of Pyongyang belongs - that of Gulag memoir - is not to diminish either the individual or collective suffering described, only to observe that human cruelty tends to lack originality. (There are, for instance, a limited number of ways in which human beings can be brutally interrogated, and you find them in accounts of torture from Buenos Aires to Abu Ghraib.) The interest, then, apart from the salutary but depressing reminder that such things are all around us, lies largely in the detail. In the case of this book, the detail is vivid and revealing.
North Korea is certainly a faraway country of which we know little. Jasper Becker, whose Rogue Regime: Kim Jong-il and the looming threat of North Korea (Oxford University Press, 2005) was one of the few recent books to chart the internal condition of North Korea, describes the country as "a Gulag with nukes". But if, as Becker argues, the essential condi-tion of North Korea's 22 million people is that of slaves in a vast labour camp, there remain, nevertheless, the officially designated labour camps - places where the general misery is distilled to produce an even more potent experience.
In 1977, when Kang Chol-hwan was just nine years old, he was sent with his seven-year-old sister and the rest of his family to Yodok camp, where he stayed for ten years. The family's crime was to be who they were - a wealthy, patriotic Korean family that had spent many years in Japan, among the substantial Korean expatriate community.
Kang's grandfather was a successful busi-nessman, his grandmother an enthusiastic communist who played a key role in the patriotic exile organisation Chosen Soren, channelling money and other support to the regime. Under her influence, the family made the disastrous decision to return to North Korea. The regime was keen to entice wealthy and well-educated Koreans back home to contribute to building the country, a tactic also used by Mao Zedong's China in the early days of the revolution. But, like many individuals and families who returned to China, most lived to regret it.
The decision of Kang's family is hard to understand in the light of the economic disaster that has engulfed North Korea in recent times. In the 1960s, however, the choice between North and South seemed - to this family at least - less clear. The North, according to Kang, seemed as prosperous then as the South, especially in the privileged showcase of the capital Pyongyang. The economic growth that would make South Korea one of Asia's tiger economies was barely beginning. In the North, the catastrophic decline that would lead to the famine of the 1990s was still just over the horizon. Politically, the choice was between a dictatorship of the right in the South and a revolution - with all the promise that implied - in the North. From the outside, the terrors of the police state - the constant surveillance, the arbitrary imprisonment, the cynical use of political disgrace to strip an individual of his assets - were not visible. By the time the returnees understood, it was too late: they were trapped.
For a while, Kang had a privileged existence: three generations of the family - seven people - lived in a spacious apartment in Pyongyang. Kang played with his friends and kept exotic fish. They toured the country in their large car. As a child, he writes, he thought of Kim Il-sung as a kind of Father Christmas, the generous father of his people. Inevitably, the day came when his grandfather disappeared into a concentration camp, another victim of the regime's paranoia, and his family was sent to Yodok. There was one exception: Kang's mother stayed behind, divorced her husband and did not see her children for more than a decade.
The camp was full of returnees from Japan, all of whom had fallen under political suspicion. As in Mao's China, just having overseas connections, or even the memory of another place and another political system, was enough to prompt your arrest. As the family arrived at Yodok, their truck was surrounded by filthy starving people with matted hair, one of whom turned out to be a family friend who had vanished a few years earlier. The family soon became indistinguishable from the dirty inmates. For the children there was schooling, followed by hard labour hauling logs; for the adults, only hard labour. They learned the survival skills of camp life - who could be trusted, how to catch rats to eat. An uncle became an informer and was rewarded with a privileged, if fraught, post in the camp's distillery. There was corruption, of course, among the guards. The family battled hunger and depression, and endured ideological "re-education". Inmates died - of hunger, disease and industrial accidents - or they were executed in view of the rest of the prisoners, who were then forced to stone the bodies.
Kang attended 15 executions during his time at Yodok and never got used to them. Yet he writes: "I don't blame the prisoners who unaffectedly went about their business. People who are hungry don't have the heart to think about others . . . I've seen fathers steal food from their own children's lunch boxes." He does not exempt himself. "Even when my grandmother was suffering from pellagra, the thought of bringing her soup only crossed my mind after I devoured a few rabbit heads. What leftovers I did bring her, she pounced on with avidity, searching furiously for any remaining shred of meat."
It was a callousness that the regime had brought to the wider society, too. "I saw fathers," Kang writes, "released from camps with their bodies broken and depleted, turned out of their children's homes, hungry mouths with nothing left to give . . . Only their demise could bring any good, by clearing the way for the family's possible rehabilitation."
After ten years, the family was released into an agricultural settlement, where Kang's father and grandmother died. He was eventually reconciled with his mother, but not with North Korea. He escaped to China, where he tried, unsuccessfully, to seek refuge in the South Korean embassy, eventually reaching South Korea by ship from Dalian.
Kang was lucky. Most people who try to escape from North Korea fail: the Chinese government returns all those it finds, and one effect of the country's rising power is to mute the protests of both South Korea and the US. Since his release, Kang has become an advocate of action against the North Korean regime. He has met George W Bush, who pronounced himself "moved". Pyongyang reacted furiously, calling Kang "human trash".
But this member of the axis of evil is not a candidate either for an assault by the US marines or for a pre-emptive strike against its military installations. Kang's story reads like a message from the past: an account of China in the 1950s and 1960s, or of the Soviet Union before the collapse. Yet it is not. The Korean Gulag continues, its misery largely concealed from the outside world.
Isabel Hilton is the author of The Search for the Panchen Lama (Penguin)