pastor we follow in the film. he is the reason we were able to shoot in places where nobody goes. nobody wants to go. the border of north korea and china, it's a more than 800 mile river border and the underground railroad and pastor kim's network keeps flip phones and cameras hidden along that border and that is how we were able to do this. >> how many people helped this one family? >> in this one escape, there were more than 50 people from the underground railroad involved in that escape. >> describe the journey because we see some of it and it feels like they're going through forests. going through jungles. and they just have the keep moving. the little kid gets hurt. the mother just says you've got to keep moving. >> yeah. so, the journey begins in china, which is a huge country. in this particular case, they