Cavalry captain Michael von Prack, a daredevil pilot in World War I, is taken prisoner by British troops in Asia Minor in 1918.
In a bar, Michael comes across a captain who is recruiting former regular soldiers to fight in a Freikorps aligned with the White movement against the Red Army.
She considers him to be his cousin, Russian general Alexej Alexandrowitsch von Prack, with whom she is in love, because the two men are as like as two peas.
While moving forward into the warzone, Michael re-meets Vera who is not only Alexej's lover, but also a Russian spy.
When Alexej learns that Vera has met his hated cousin who is the commander of the enemy troops, he swears him death and sets a trap for the Freikorps by luring them into a swamp.
Although Vera recognizes him immediately, Michael is able to act as the general and to discover important military secrets.