The little group spent two days in Beijing before catching the train south. For those brought up in isolation in a Stalinist state, China's capital would have seemed overwhelming. The new high-rise office blocks, the shopping centres and the traffic all in stark contrast to the economic conditions in Kim Jong-il's bankrupt state.
At the main station we filmed secretly as the little group passed the final ticket check and boarded the express.
For the next 50 hours they stayed hidden in their bunks avoiding all contact with other passengers, terrified their North Korean origins would be detected and an informer would turn them in.
At a railway station near a south Asian country bordering China the four by-now exhausted refugees melted into the crowds on the streets outside the station without a backward glance - the children holding their mother's hands.
Our presence would only jeopardise the last border crossing that, if successful, would see them safe from the clutches of the Chinese police.
We still don't know if they made it.
But that won't stop hundreds of other refugees making that same perilous journey as Kim Jong-il's bankrupt socialist 'paradise' lurches towards free fall.