Anna Sten is Nadine, the Ukrainian assistant to a scientist (Harry Davenport) and preparing to become an American citizen. On the eve of the ceremony Soviet spies led by her "boyfriend" Paul Brandt (Jerome Cowan) - not that she knows his real intentions towards her - kill the scientist to get their hands on a potential chemical weapon. However they need Nadine to translate the notes, but she is on a train heading across the country to be deported having being suspected of involvement in the scientist's death.
Reporter Steve (Alan Marshall) is also on the train covering another story. He becomes interested in Nadine and gets involved when she makes a getaway. He even ends up becoming married to her! However not only are the police after them, Brandt and his gang are too...
Although often ridiculous, and with a bit too much lightness thrown in at times - some of the "comedy" characters are simply bizarre and tedious apart from the raving lunatic Bolshevik. The film is an enjoyable romp with some chase scenes but quite a lot of filler, luckily Anna Sten and Alan Marshall do a good enough job to keep you interested.