Plot
An early morning walker discovers the body of a woman, film star Christine Clay at the edge of the surf on a beach in Kent. People hope she is the victim of a drowning accident, but the presence of a button tangled in her hair, and signs of struggle on her hands, lead Inspector Grant to conclude she has been murdered.
Grant’s suspicion quickly falls on her house guest, Robert Tisdall, who admits to having stolen Clay's car and then regretted it and returned to the beach. Tisdall had been Clay's guest for four days at the time of the murder, in a cottage that she had rented in secret to have an anonymous holiday, as only her husband and the owner know where she is. Tisdall inherited a fortune but has squandered it, is shaken, and was rescued when Clay randomly encountered him in London, offering him hospitality out of kindness. She did not tell him her full name, instructing him to call her "Chris".
Clay's identity is revealed when Jason Harmer, her songwriter, arrives at the cottage having tracked down its location from a clue in a letter he received from her. Once her identity becomes public Lydia Keats, an astrologist, receives considerable attention for having correctly predicted that Clay would drown.
The day before the murder, Clay wrote to her lawyer instructing him to add a codicil to her will bequeathing a small portion of her estate — a ranch in California and several thousand pounds — to Tisdall. The bulk of her estate is left to "maintain the beauty of the English countryside", as she knows her husband has sufficient wealth.
Tisdall does not know about the bequest to him until police tell him.
Although it goes against his intuition, Grant is convinced of Tisdall's guilt by the motive provided by the bequest. Another suspicious circumstance is that Tisdall's coat, which has buttons similar to the one found in Clay's hair, has been stolen.
Grant decides to arrest Tisdall, but he escapes. Later, Erica Burgoyne, the 16-year-old daughter of the local Chief Constable finds Tisdall and brings him food. Erica believes Tisdall's story about his coat, and sets out to find it. She does find it, with no missing buttons, leading Grant to conclude that Tisdall is innocent. Tisdall cannot be found and anxiety mounts regarding his safety.
Grant is back at square one. He next investigates Clay's brother Herbert Gotobed, who turns out to be a con man with a history of posing as a religious prophet.
Clay's husband, Lord Edward Champneis (pronounced “chins”). Champneis arouses suspicion by failing to account for his whereabouts on the night before the murder, but Grant is reluctant to confront him.
Lydia Keats gives a talk about astrology. Her audience, including actors, actresses, aristocrats and one police officer, really wants to hear about her foretelling one year earlier that Clay would die. Lydia blurts out that Clay’s killer is in the room; that statement drives the frightened audience out in a crush.
Grant tracks Gotobed to a monastery in Canterbury, not far from Clay's cottage, where he is on the point of being given control of a large amount of money as Prior to the brotherhood's Mexican mission. Eventually Gotobed is arrested for his stash of phony passports, and extradited to the US.
Champneis's suspicious behavior is due to an effort to help a political exile to obtain sanctuary in London. Tisdall re-surfaces, having hidden in an attic for several days; he is feverish and on the point of pneumonia but recovers.
At a loss for the next step, Grant decides to get a haircut. While waiting, he happens across an article in an old magazine that points out how celebrated Lydia Keats will be if her prediction of death by drowning for a film star — not identified in the article — comes true, and hints that the star should not go swimming with Keats for fear she might be tempted to make her prediction a reality. He telephones the cottage's owner Owen Hughes and finds that he mentioned Clay's tenancy of the cottage to Keats, forgetting that it was supposed to be a secret. Keats has a motorboat that could have given her easy access to the beach where Clay was killed. Grant investigates and finds a coat in the motorboat that is missing a button on one sleeve. He confronts Keats. She raves about her infallibility and the glorious destiny predicted for her by the stars, and is taken away by the police surgeon.
The final scene of the book is a dinner party attended by Grant and Tisdall at the Burgoyne home. Grant is happy to see that Erica is still her young and independent self, and has not fallen for Tisdall.
