In “The Old Man and the Child,” the first of the three parts of The Oath, Azriel begins telling a young man a little about Kolvillag, his native village, somewhere in central Europe between the Dniepr River and the Carpathian Mountains. Kolvillag had been ruled by several nations but no longer exists. “I am Kolvillag,” says Azriel, “and I am going mad.” His madness results from an oath not to tell the secret of his village.

The young man learns that Azriel is highly regarded for his extensive learning by a wide variety of people: “He made them understand what was happening to them; it was always more serious or simpler than they had imagined.” Because Azriel cannot tell his friend more about Kolvillag, he talks instead about his life after leaving there, about wandering through Europe during the years between the two world wars, and about Rachel, the only woman who has ever mattered to him.

The young man is tormented by memories of his mother, a survivor of the Nazi concentration camps who lost her first husband and son in the Holocaust. Because the young man has been contemplating suicide, Azriel decides to break his oath of fifty years: “I’ll transmit my experience to him and he, in turn, will be compelled to do the same.... He must stay alive until he has transmitted his message.” This message is contained in the Pinkas, the history of Kolvillag kept over many generations, the last chronicler being Shmuel, Azriel’s father, the official registrar of the community.

The events leading to the destruction of Kolvillag are described in part two of The Oath, “The Child and the Madman.” The trouble begins when Yancsi, a Christian youth and bully, disappears and is presumed killed. The Gentiles of Kolvillag assume that Jews are responsible, but the Jews consider the thought of ritual murder in the twentieth century ridiculous. The Prefect of the village at first promises to keep the Jews safe but later says that a pogrom is inevitable.

The Oath then becomes the story of Azriel’s friend and mentor, Moshe, who volunteers to be the scapegoat. Moshe is a religious scholar and mystic who claims to be able to read minds but chooses to live in isolation. He is satisfied to be thought a madman and to teach all that he knows to Azriel. The rabbis argue that Moshe’s offer of self-sacrifice is pointless and is a rejection of God, but he goes to the police anyway and is savagely beaten. Davidov, the leader of the Jewish community, seeks help from the attorney Stefan Braun, a Jew who does not live as a Jew. Braun declines to help because, as he tells his son, “The era of crusades and pogroms is gone. Ours is dominated by humanism, liberalism.”

Moshe’s sacrificial offer is rejected by the Christian authorities, who are convinced, however, more than before that Jews are behind Yancsi’s death. Addressing his fellow Jews at the synagogue, Moshe makes them swear an oath that whoever survives will not reveal what is about to happen since knowledge of previous atrocities has not stopped the pogroms over the centuries.

The ensuing slaughter is described in graphic detail in the final section, “The Madman and the Book.” Shmuel passes the Pinkas on to Azriel, asking his son to be their witness. Before escaping, Azriel sees the Christians, driven mad by blood lust, turn against one another. He also sees Yancsi, who has returned in time to die. Azriel is the only survivor of Kolvillag. The Oath ends with the young man assuming the memory of Kolvillag.