In London, August 1914, Austrian star Elsa Duranyi (Gertrude Michael) and English matinee idol Alan Barclay (Herbert Marshall) are in love and plan an immediate marriage. But the War comes and Elsa mysteriously disappears. Alan's ease in speaking German results in his appointment to the British Intelligence and, to aid his use as a spy, they announce he was killed in action. He takes the name and personality of "shell-shocked" Hans Teller, a German prisoner, and is sent into Germany on an exchange of prisoners.