In 1949, guilt-ridden Holocaust survivor Herman Broder lives in New York with his wife, Yadwiga. During the war, Yadwiga—the Broders' gentile servant—saved Herman's life by hiding him in a hayloft. Believing his wife, Tamara Broder, to have perished in a concentration camp, Herman took Yadwiga with him as his wife when he emigrated to the United States. He tells her that he works as a traveling book-salesman; however, in reality, he is a ghost writer for the avaricious Rabbi Lembeck. He also is having an affair with Masha, whose own experiences in a concentration camp have left her embittered about God and Judaism; she emigrated to New York with her mother and married Leon Tortshiner, an older man from whom she is estranged. Masha wants them to divorce their respective spouses and get married, but he continually puts her off.
After answering an ad in the newspaper, Herman is shocked to learn that Tamara not only survived the Holocaust, but has come to New York to be with him. Herman confesses to her both his current marriage and affair. Accepting that he has moved on from her emotionally, Tamara agrees not to pursue her claim as his wife and befriends him. In short order, both Masha and Yadwiga announce each is pregnant. Masha procures a divorce from Leon, who warns Herman that Masha is manipulative. After she swears on her own life that Leon is lying about her, Masha and Herman find a Rabbi to perform the ceremony without asking questions. Herman now has three wives.
Masha experiences internal bleeding, and the attending physician tells Herman that she was never pregnant. Rabbi Lembeck, having met Masha, invites the couple to a party. There, the wealthy Nathan Pescheles - who happened to meet all three wives by chance - reveals Herman's polygamy to the assembled crowd. Feeling angry and betrayed, Masha leaves Herman. He becomes more religious to help Yadwiga convert to Judaism. Tamara helps him by getting him a job with a rabbi.
A few weeks later, Masha calls Herman, hoping to convince him to bolt to Florida or California with her. Admitting to Tamara that Masha's pull on him is too great but promising to support his unborn child, Herman leaves Yadwiga for good. But before they can leave, Masha's mother dies. Unable to pay for the funeral but realizing she can't bear the thought of not being buried next to her mother, Masha asks Herman to commit suicide with her. Herman agrees, but when they realize neither has ever been completely truthful with the other, he leaves. Masha takes a lethal overdose of sleeping pills.
Rabbi Lembeck pays for Masha and her mother's funeral and takes care of the hospital fees for Yadwiga. Tamara and Yadwiga raise the child, named Masha, together. Letters occasionally arrive containing only money to help care for the child.
