Destination Unknown plot
"Two Against Jap Treachery!"
Elena Varnoff is a spy from the Netherlands who tries to find out the whereabouts of the "Saint Petersburg" jewels in Shanghai. She suspects Karl Renner, a German spy who is collaborating with the Japanese. Elena gets help from Briggs Hannon, and while searching Renner's apartment, the two come across a photo of Beijing Sun Wat Lin, the last man in possession of the jewels. Hannon also finds a timepiece with a secret code that can lead to the jewels. He doesn't tell Elena about his find. The two take the train to Beijing and are followed by Renner.