He had packed two backpacks the night before, containing food and spare clothes, plus a knife and poison.
He wasn’t taking any chances, and was also taking a gun. Kim tried to persuade him to leave it behind but Jeon was adamant.
Surviving capture wasn’t an option. A show trial in North Korea and execution would almost certainly be the punishment – particularly since the guard was absconding with a prisoner.
“I knew I had only that night. If I didn’t make it that night I would be captured and killed,” says Jeon Gwang-jin, 26.
“If they stopped me, I was going to shoot them and run. If I couldn’t run, I was going to shoot myself.”
If that didn’t work he was going to stab himself with the knife and take the poison.
“Once I was prepared to die, nothing scared me,” says Jeon.
Together they jumped from a window and dashed across the detention centre’s exercise yard.
Ahead of them lay a high fence that they would have to scale, and the fear that the guards’ dogs, which they could hear barking, would give them away.
It was an unlikely friendship – the prison guard and the prisoner.
They had met just two months earlier – in May 2019. Jeon was one of several guards at Onsong Detention Centre in the far north of North Korea. He and his colleagues kept Kim and a few dozen other inmates under surveillance 24 hours a day whilst they awaited trial.
Kim caught his eye with her refined clothing and demeanor.
He knew she was there because of her role in helping their fellow countrymen who had already fled a life of desperation.
Kim was what was known as a broker. She helped keep channels open between those who had fled and families left behind. This could mean facilitating money transfers or phone calls from the defectors.
And it was lucrative work for the average North Korean.
Kim was paid about 30% of the cash as commission, and an average money transfer is about 2.8m won [£1,798], research suggests.
On the face of it, Kim and Jeon couldn’t have been more different.
While she made her money illicitly, learning as she did about the world outside North Korea’s strict communist regime, Jeon had spent the past 10 years in the military as a conscripted soldier. He was steeped in the communist ideology of the country’s dictatorship.