Transcript for 'An Inconvenient Border' clip 2: China's hidden bridge to North Korea

She opened the game. I. A series of saves time and he's sneaking in sand underneath a bridge. So yeah. Okay. This gets got a mysterious ways thinking. Justice like a secret place room. Do you know any defectors have ever come here. Yeah. You know on this story and what he told. We have never get over and you can go that do you have the bottom. Infusion long gone you get solution for what is what is the tensions as tension because of the the nuclear tests. And on jesus' Levy's attorney how many Kia and preview glam none of the Americans more than. How Koreans for stopping this tourism to a trio curious how many are costly. Yet different what are you Sunday in Hong. Calling you nervous about being interviewed. KF. Nerves apparently called the tour guide offers to take this further to the new bridge in town. One. It's Paul Clement. This is C of Britain had here. To really here. Susie concerned about the police. On the on the court brief you on before in community but yet on his. That's a prison right there. Please hold on to move on did. It's impossible as it can help them build this bridge. But the bloody can German want to build this bridge and four war are greatest. So was Kim Jung and 740 years from. He tells us his friends in the Chinese military told him about the bridge which he says is just wide enough for two tanks to go across at the same time. It's meant to the North Korean generals to get over the border if the war breaks out. Once we get back and our fans the tour guide. Speeds off.

This transcript has been automatically generated and may not be 100% accurate.