A woman helped by Germans marries an American consul, who is trained for the foreign service; but he has to resign because of her and spy unofficially.
In 1915 sabotage is suspected in America. In 1939 Americans feel threatened in Tangiers and turn to consuls Barry Corvall (Joel McCrea) and Lowell Warrington (Jeffrey Lynn). In the rain Brenda Ballard (Brenda Marshall) goes to Germans, says she is American, and asks for a passport. Barry and Lowell are warned about spies. Brenda comes in and faints. She tells Barry she has neither family nor friends. Barry helps her take the same ship as he and Lowell and gives her their room. Barry asks Brenda to marry, but she won't because of his career. Barry's mother (Nana Bryant) asks him about Brenda.
Barry and Lowell study for the foreign service and are warned about spies and saboteurs. Barry is assigned to France and Lowell to Geneva. Barry brings Brenda to the ball and tells his mother they got married. Brenda sees the German Karl Mullen (Martin Kosleck), who tells her what to get. Brenda tells Barry that Mullen is a spy, that she was desperate in Europe for any job. Barry asks her to tell about Mullen, who is summoned and questioned. Barry says Mullen is a spy, and Mullen says Brenda is a spy. Barry resigns. He tells his mother and Brenda that Mullen went free because of the laws. Barry says he'll try to get the laws changed to prevent sabotage. Brenda persuades Barry to let her go with him.
In Geneva Brenda goes out alone and tells Paul Strawn (Rudolph Anders) that she will get keys to a code. She tells Barry what they want. Barry calls on Lowell and says he suspects Brenda. Lowell verifies it is their code; a porter overhears and calls. Barry asks Lowell for a chance to clear Brenda. She warns Barry about the porter. Dudley Garrett (George Bancroft) gives news on radio to Americans. Brenda turns in code notes to Dr. Rader (James Stephenson) and is paid. Barry snoops on Rader and overhears their plans. Barry tells Garrett about them but says he needs proof, asking for a chartered plane. Barry tells Lowell about Rader as the porter listens. Brenda goes to Rader and says Barry knows about him. Barry tells Lowell to lock up the porter. Rader thanks Brenda and makes her leave with him. Barry follows but is stopped by another car. Lowell tells Barry where Rader went. Barry takes the plane. On the train Rader tells Brenda they know about her. Barry comes in with a gun and knocks out Rader. Barry and Brenda get off the train and on the plane. Barry, back in America, gets Congress to pass anti-espionage legislation and is commended by the foreign service and his mother; then he kisses Brenda.
This drama was released only a few weeks after Germany invaded Poland and clearly reflects American concerns about the war and the dangers of sabotage on its powerful industrial installations. Thus it makes a strong appeal for renewed legislation to repress espionage efforts.