When John North, a budding author, pulls the communication cord of a late night train that is taking him away on a weekend with his publishers wife, he sets in motion a series of events that lead to a train crash, a murder and a police man hunt, but all is not what it seems.
Charters and Caldicott are touring the Middle East. After visiting Saudi Arabia they find themselves in Bagdad where they are mistaken by a group of German spies for the messengers who are to carry a song record by beautiful singer La Palermo which contains secret instructions of the German Intelligence. Realizing their error, the German spies follow Charters and Caldicott to Istanbul and Budapest, trying to eliminate them and retrieve the record.
An evil doctor and the greedy wife of a rich man plot to poison him so they can get their hands on his money.
