The four main characters are Temple Drake Stevens; her husband, Gowan Stevens; her former friend Nancy Mannigoe, who was also their baby’s nanny; and Gavin Stevens, Gowan’s uncle and Nancy’s defense attorney. Nancy is African American; the other main characters are white. The plot revolves around Nancy’s murdering the baby before the novel’s action starts. Nancy is tried and convicted of the murder, and sentenced to death. Temple, Gowan, and Gavin debate the fairness of the sentence and even consult the state governor about a reduction.

As a character in William Faulkner’s earlier novel Sanctuary, Temple Drake had been abducted by a pimp and coerced into prostitution. Her father had located her and sent her abroad. In the interval before Requiem for a Nun begins, Temple has married Gowan Stevens; they have two children, a son and baby daughter. Just before the second novel opens, Temple has been blackmailed about her past and planned to run away with another criminal, and Nancy has killed the baby.

Gowan Stevens, Temple’s husband, had also featured in Sanctuary; he was an alcoholic whose carelessness led to Temple’s abduction. Although he abandoned her at that time, he later re-entered her life and they married.

The attorney Gavin Stevens is Gowan’s uncle. He defends Nancy Mattigoe in the murder case. Gavin also appears in other Faulkner fiction. Gavin is a fair and just man, who tries to get a stay of execution for Nancy. He and Temple visit the governor and explain the circumstances that led to the murder.

Nancy Mannigoe was the nanny for Temple’s baby daughter. Temple had met and become friends with Nancy when both were prostitutes; at that time Nancy was also addicted to drugs. There is no question that Nancy killed the baby; she did so by smothering her in her crib while Temple was in the next room. The violent act was her misguided effort to compel Temple not to leave with her criminal former boyfriend but to stay with her husband and other child.

Pete is Temple’s former lover who returns to her life. He blackmails Temple over some letters from her past. In her home, when he seems to have convinced her to leave with him, Nancy intervenes by killing the baby.