When she returns to her office from the funeral service, she is visited by her first client, Elizabeth Leaming, assistant to prominent scientist Sir Ronald Callender, whose son Mark recently hanged himself.

Cordelia travels to Cambridge, where Mark had left university and taken a job as gardener, despite decent grades and the prospect of a considerable inheritance from his maternal grandfather.

Repeatedly, friendly overtures from Mark's former companions try to lead her away from the investigation but Cordelia is determined to succeed in her first solo case.

The old woman tells Cordelia that she went to see Mark at his college and gave him a Book of Common Prayer that his mother had wanted him to have when he turned 21.

Cordelia sympathises with Miss Leaming and is determined to protect Mark's legacy, so the two rearrange the crime scene to look like yet another suicide and it is accepted as such by the coroner.

Word arrives during their interview that Leaming has been killed in a car crash, allowing Cordelia to maintain the fiction they concocted together.

He also believes that he has worked out the true facts of the case, but in private conference with his superiors says there is little point in disturbing the official story in view of the social and international pressures on the police.

The New York Times judged the book "A top-rated puzzle of peril that holds you all the way",[3] whose characters "are anything but stereotypes," although "at the very end, things are a little too pat".

[6] Authors commenting on the introduction of the new type of female detective noted the novel as a key pioneering work in which the focus is "at least as much on character and theme as…on crime".

[11] In contrast to the detectives that predate the novel, Cordelia continually questions the morals of the people she encounters, and is also motivated by achieving justice for Mark.

Based on her successful detection as an independent, "morally upright" woman, Cordelia was frequently viewed as a "hero" around the time of the novel's release.

A television series starring Helen Baxendale as Cordelia and Annette Crosbie as Edith Sparshott was made in 1997 and 2001, based in part upon the book.