The old habits of secrecy haven’t left Kim Kuk-song.
It has taken weeks of discussions to get an interview with him, and he’s still worried about who might be listening. He wears dark glasses for the camera, and only two of our team know what we think is his real name.
Mr Kim spent 30 years working his way to the top ranks of North Korea’s powerful spy agencies. The agencies were the “eyes, ears, and brains of the Supreme Leader”, he says.
He claims he kept their secrets, sent assassins to kill their critics, and even built an illegal drugs-lab to help raise “revolutionary” funds.
Now, the former senior colonel has decided to tell his story to the BBC. It’s the first time such a senior military officer from Pyongyang has given an interview to a major broadcaster.
Mr Kim was the “reddest of the red”, he says in an exclusive interview. A loyal communist servant.
But rank and loyalty do not guarantee your safety in North Korea.
He had to flee for his life in 2014, and since then he has been living in Seoul and working for South Korean intelligence.
He depicts a North Korean leadership desperate to make cash by any means possible, from drug deals to weapons sales in the Middle East and Africa.
He told us about the strategy behind decisions being made in Pyongyang, the regime’s attacks on South Korea, and claims that the secretive country’s spy and cyber networks can reach around the world.
The BBC cannot independently verify his claims, but we have managed to verify his identity and, where possible, found corroborating evidence for his allegations.
We contacted the North Korean embassy in London and the mission in New York for a statement, but have so far received no response.
Mr Kim’s last few years in North Korea’s top intelligence unit offer some insight into the early career of the current leader, Kim Jong-un. He paints a picture of a young man eager to prove himself as a “warrior”.
North Korea formed a new spy agency called the Reconnaissance General Bureau in 2009, just as Kim Jong-un was being groomed to succeed his father, who had suffered a stroke. Chief of the bureau was Kim Yong-chol, who remains one of the North Korean leader’s most trusted aides. -BBC