In the wake of the Russian Revolution, Stephen Locke, a young British diplomat, argues that Great Britain must recognize the provisional government in order to prevent them from establishing a separate peace with the Germans, which would free German soldiers to face the remaining allies on the Western front. The night that the provisional government falls to Lenin's party, Stephen witnesses Elena Moura shoot a Cossack who is attacking a woman and her child. He helps her escape into the embassy and learns that she is a Communist. Most of the Allies close down their embassies, leaving behind only a token staff. Bored and frustrated by their inability to act, Stephen, LeFarge, the French representative, Tito Del Val, the Italian, and Bob Medill, the American, spend their days playing cards and their nights in a gypsy cafe. One night, Elena comes into the cafe and Stephen persuades her to leave with him. Although politically they are on opposite sides, they fall in love, but Elena's first loyalty is to her country, as she proves when she informs the Central Committee that Stephen is not Britain's official ambassador. Betrayed by the woman he loves, Stephen is also let down by his country, which once again ignores his advice. When the Czar is assassinated, the White army tries to reorganize and Stephen, LaFarge, Medill and Del Val come to their aid. An attempt is made against Lenin's life by Dora Kaplan, and the Russian secret police ask Elena to provide evidence of Stephen's counter-revolutionary actions. She agrees but when she learns that the Russians intend to explode the warehouse where Stephen is hiding, she joins him there, intending to die with the man she loves. Just as the soldiers are about to kill them, Lenin recovers from his wounds and pardons all political prisoners. Elena and Stephen leave for England to start a new life together.