Dr. John Berry, the protagonist, is a pathologist working in Boston during the 1960s, a time when abortion was illegal in the United States. The story opens with an introduction of the various requirements and challenges of the medical profession during the era. Subsequently, Dr. Berry is notified that his friend, an obstetrician named Arthur Lee, has been arrested and accused of performing an illegal abortion that led to the death of Karen Randall, a member of a prominent Boston medical dynasty. Berry does not believe the allegations, but the situation is further complicated by the fact that Lee is already well-known within the medical community as an abortion provider and that Berry has in the past helped Lee disguise medical samples to hide the fact that Lee's dilation and curettage patients were pregnant.
After visiting his friend in jail, Berry sets out to prove Lee's innocence. He investigates the personal life of the dead woman, creating an accurate portrait of her past, psychology, and character. During his search, which lasts several days, vandals attack Lee's home. The protagonist's knowledge of medicine and law are helpful in overcoming various barriers in his search, including a hostile police captain and bribes from the scion of the Randall family itself: Karen's father, a well-established (though mediocre) doctor.
Eventually, with the aid of an unscrupulous African-American lawyer, Wilson, Berry is able to obtain solid evidence showing Karen Randall's uncle (who had already performed three previous abortions for her) to be the culprit. Nonetheless, Berry is troubled by this conclusion and continues his investigation despite Wilson's displeasure. Eventually, he discovers that Karen's drug-dealing friends, Roman and Angela, performed the botched abortion, but Berry is attacked and sent to the hospital before he can reveal his discovery. Subsequently, Berry's attacker, who turns out to be Karen's African-American boyfriend, is also brought in an ambulance, dead after a fatal fall. The actual abortionist attempts to commit suicide. Berry forces her to confess in the hospital by threatening her with what she believes is an excruciatingly painful dose of Nalorphine (but is actually water).
Berry continues to be suspicious about Karen's boyfriend's death, and ultimately forces one of his old friends and colleagues (the uncle of the woman who did Karen's abortion) to admit to his involvement before turning him in to the police. However, despite being proven innocent, Lee's reputation has been ruined, and he decides to move to California. The novel ends with several appendices describing some lesser-known aspects of the medical profession and a postscript discussing current problems in medicine, including abortion.