Passport to Danger - Season 1 Episode 37 Ankara

On an airplane Steve meets two children traveling alone who refuse to give their last name. When their aunt fails to meet them at the airport, Steve takes pity on them and allows them to stay in his hotel room. The children's aunt finally arrives, but Steve learns too late that a Romanian industrialist has fled to Crete with a large sum of money and the "aunt" is actually a communist agent who plans to use the children as hostages to force the defector to return behind the Iron Curtain.