Adventures of Superman

Superman meets the two people in a theater in a country "behind the iron curtin". Behind them is a door with a sign above it that clearly reads "EXIT". A theater in Eastern Europe would not have signs in English. There is also a plot flaw. When told of the history of the jewels he responds to the two people by assuring them that he would check up on their story. Superman meets them the following night in Paris where the phoney policemen kidnap the two and then steal the gems. Had Superman really checked on the claim, he would have known immediately that the policemen were fakes.