The unsuspecting Tom goes to a nearby tavern one night, where he meets a Polish refugee named Linda Pavlo and strikes up a conversation with her.

Curtis breaks the news to Prescott that the East Coast plant has been compromised and sabotaged by George Pembroke, one of its own chemists now identified as working for the Nazis under the name of Karl Schmidt, who stole half of the formula,.

When Tom leaves the tavern that night, he is again followed by one of Curtis' men, but one of Gemmler's spies (in the disguise of a blind beggar) murders the agent.

The following day Prescott and Curtis talk to Robert, explaining their theory that Tom, in an act of treason, has murdered the agent.

The spies bring Tom with them to the airport, where Gemmler's contact, Karl Schmidt, is about to arrive on 'the Dawn Express'.

Principal photography on The Dawn Express with the working title of Nazi Sky Ring, began January 30, 1942, at Sunset Studio.

[3] The Dawn Express was typical of the films produced early in World War II that concentrated on enemy espionage.

[4] The Dawn Express was not critically reviewed, as the film was a low-budget production that, other than featuring the steady and reliable Nagel, who appeared in a bevy of "light leading roles" during this period, had little to offer.