There Were Lost CIA Agents In North Korea
North Korea has been a mystery to the US intelligence agencies for decades now. In the 1950s, they set out to learn more about the country by parachuting CIA agents into the country. They hoped the agents could plant seeds of resistance and lead the North Korean people against the government.
The agents who dropped in were never heard from again. Apparently the CIA continued to send agents into the hermit country until 1970.