Cordelia Gray, Pippa Guard, inherits a private detective agency after her former boss Bernie Pryde dies and leaves her the business, and she takes on a high-profile case: the suicide of Mark Callendar, Alex Guard, a gifted university student from a powerful family who abruptly abandons his studies, moves to a remote cottage, and takes work as a gardener and handyman before hanging himself.
The assignment comes from Mark’s father, James Callendar, Paul Freeman, a prominent real estate developer, and his aloof assistant Elizabeth Leaming, Billie Whitelaw. Cordelia first visits the cottage where Mark died and speaks with Miss Markland, Elizabeth Spriggs, the property owner who found the body.
She then travels to the Callendar country house, where Elizabeth Leaming keeps her company and shows Cordelia home movies of Mark. There Cordelia is introduced to Andrew Lunn, Dominic Guard, a family friend and elder mentor figure to Mark.
Next, Cordelia meets Isobel, Isobel Dawn Archibald a university friend who treats the inquiry with suspicion, as if she suspects Cordelia of chasing a journalist’s scoop. From the coroner’s report, purple lipstick traces on Mark’s mouth suggest a woman kissed him before his death, prompting Cordelia to suspect Isobel.
Isobel recounts how she discovered Mark’s body in the cottage that night, claiming Mark was wearing women’s underwear and lipstick, and that she phoned Andrew but left the body untouched. When Cordelia questions Andrew, he says he visited Mark’s body but denies the presence of such clothing or lipstick, complicating the case further.
Back at the cottage, Cordelia attempts to recreate Mark’s suicide using crime-scene photographs and the belt he fashioned, but the drill goes awry when she nearly hangs herself; a young boy witnesses the peril from outside the window and screams for help. That boy is James Gilbey, who plays the role of a Boy in the household.
A tense confrontation follows when Andrew confronts Cordelia, and clues in a prayer book—found in Mark’s cottage—lead Cordelia to a troubling conclusion: Mark’s birth mother Eve was not his biological mother. The book had been recently given to Mark by Elizabeth on his 21st birthday, a detail that deepens the mystery surrounding the Callendar estate.
Elizabeth invites Cordelia back to the cottage to discuss the matter, but the night takes another dangerous turn when Andrew hides in an upstairs closet and drags Cordelia toward a well on the property. She manages to crawl out and, from a distance, watches as Andrew drives off a bridge into a river, killing himself.
Returning to the Callendar estate, Elizabeth finally reveals the larger truth: she admitted to having given birth to Mark on Eve’s behalf, fulfilling James’s desire for an heir. Elizabeth explains she delivered Mark in Italy and that the two of them were involved in a contractual arrangement, and she admits to having removed the lingerie and lipstick from Mark’s body and to having summoned Cordelia to investigate.
Cordelia pieces together the motive: James Callendar murdered Mark, furious at his son’s defiance and the secret about his birth, and staged the death to look like a suicide. The revelation culminates near the river where Andrew died, with James present and defiant. When Cordelia accuses him, James denies the charge, but Elizabeth steps in and shoots him dead, after which authorities quickly take Elizabeth away.
In the wake of the confrontation, Cordelia recognizes how the family’s wealth and pride intersected with fear, secrecy, and control, and she leaves with a renewed sense of purpose about the lives she can touch as a private investigator.
